bims-celmim 2024-02-18 papers

bims-celmim

Biomed News

on Cellular and mitochondrial metabolism

Issue of 2024‒02‒18
29 papers selected by
Marc Segarra Mondejar, University of Cologne

Mitochondrial Calcium Transport During Autophagy Initiation.
The cell biology of ferroptosis.
Fusion-fission-mitophagy cycling and metabolic reprogramming coordinate nerve growth factor (NGF)-dependent neuronal differentiation.
Glutaminase potentiates the glycolysis in esophageal squamous cell carcinoma by interacting with PDK1.
GLUT1-mediated glucose import in B cells is critical for anaplerotic balance and humoral immunity.
Renal aging and mitochondrial quality control.
Ceramides and mitochondrial homeostasis.
Did mitophagy follow the origin of mitochondria?
Transcellular Barriers to Glucose Delivery in the Body.
BRD4-mediated epigenetic regulation of endoplasmic reticulum-mitochondria contact sites is governed by the mitochondrial complex III.
Enhancing mitochondrial pyruvate metabolism ameliorates myocardial ischemic reperfusion injury.
The HRI branch of the integrated stress response selectively triggers mitophagy.
A system for inducible mitochondria-specific protein degradation in vivo.
A neuron-glia lipid metabolic cycle couples daily sleep to mitochondrial homeostasis.
A self-immolative near-infrared fluorescent probe for identification of cancer cells and facilitating its apoptosis.
Cysteine induces mitochondrial reductive stress in glioblastoma through hydrogen peroxide production.
Phospholipids with two polyunsaturated fatty acyl tails promote ferroptosis.
VHL suppresses autophagy and tumor growth through PHD1-dependent Beclin1 hydroxylation.
Single-nucleoid architecture reveals heterogeneous packaging of mitochondrial DNA.
Mechanisms and functions of protein S-acylation.
Metabolic rewiring and autophagy inhibition correct lysosomal storage disease in mucopolysaccharidosis IIIB.
Decoding Serine Metabolism: Unveiling Novel Pathways for Evolving Cancer Therapies.
Multi-omic profiling of clear cell renal cell carcinoma identifies metabolic reprogramming associated with disease progression.
Structural basis for regulated assembly of the mitochondrial fission GTPase Drp1.
Proline restores mitochondrial function and reverses aging hallmarks in senescent cells.
A mechanism of lysosomal calcium entry.
Role of ketogenic diet in neurodegenerative diseases focusing on Alzheimer diseases: The guardian angle.
SLC25A51 decouples the mitochondrial NAD+/NADH ratio to control proliferation of AML cells.
Hijacking of nucleotide biosynthesis and deamidation-mediated glycolysis by an oncogenic herpesvirus.

Mitochondrial Commun. 2024 ;2 14-20

Mitochondrial Calcium Transport During Autophagy Initiation.

Sujyoti Chandra, Parul Katiyar, Aarooran S Durairaj, Xinnan Wang.

  While it has been shown that Ca2+ dynamics at the ER membrane is essential for the initiation of certain types of autophagy such as starvation-induced autophagy, how mitochondrial Ca2+ transport changes during the first stage of autophagy is not systemically characterized. An investigation of mitochondrial Ca2+ dynamics during autophagy initiation may help us determine the relationship between autophagy and mitochondrial Ca2+ fluxes. Here we examine acute mitochondrial and ER calcium responses to a panel of autophagy inducers in different cell types. Mitochondrial Ca2+ transport and Ca2+ transients at the ER membrane are triggered by different autophagy inducers. The mitophagy-inducer-initiated mitochondrial Ca2+ uptake relies on mitochondrial calcium uniporter and may decelerate the following mitophagy. In neurons derived from a Parkinson's patient, mitophagy-inducer-triggered mitochondrial Ca2+ influx is faster, which may slow the ensuing mitophagy.

Keywords:  ER Ca2+ transient; IP3R; MCU; Parkinson; RyR; autophagy; mitochondrial Ca2+ uptake; mitophagy

DOI:  https://doi.org/10.1016/j.mitoco.2024.01.002
Nat Rev Mol Cell Biol. 2024 Feb 16.

The cell biology of ferroptosis.

Scott J Dixon, James A Olzmann.

Ferroptosis is a non-apoptotic cell death mechanism characterized by iron-dependent membrane lipid peroxidation. Here, we review what is known about the cellular mechanisms mediating the execution and regulation of ferroptosis. We first consider how the accumulation of membrane lipid peroxides leads to the execution of ferroptosis by altering ion transport across the plasma membrane. We then discuss how metabolites and enzymes that are distributed in different compartments and organelles throughout the cell can regulate sensitivity to ferroptosis by impinging upon iron, lipid and redox metabolism. Indeed, metabolic pathways that reside in the mitochondria, endoplasmic reticulum, lipid droplets, peroxisomes and other organelles all contribute to the regulation of ferroptosis sensitivity. We note how the regulation of ferroptosis sensitivity by these different organelles and pathways seems to vary between different cells and death-inducing conditions. We also highlight transcriptional master regulators that integrate the functions of different pathways and organelles to modulate ferroptosis sensitivity globally. Throughout this Review, we highlight open questions and areas in which progress is needed to better understand the cell biology of ferroptosis.

DOI: https://doi.org/10.1038/s41580-024-00703-5
FEBS J. 2024 Feb 16.

Fusion-fission-mitophagy cycling and metabolic reprogramming coordinate nerve growth factor (NGF)-dependent neuronal differentiation.

Ilaria Goglia, Ewelina Węglarz-Tomczak, Claudio Gioia, Yanhua Liu, Assunta Virtuoso, Marcella Bonanomi, Daniela Gaglio, Noemi Salmistraro, Ciro De Luca, Michele Papa, Lilia Alberghina, Hans V Westerhoff, Anna Maria Colangelo.

  Neuronal differentiation is regulated by nerve growth factor (NGF) and other neurotrophins. We explored the impact of NGF on mitochondrial dynamics and metabolism through time-lapse imaging, metabolomics profiling, and computer modeling studies. We show that NGF may direct differentiation by stimulating fission, thereby causing selective mitochondrial network fragmentation and mitophagy, ultimately leading to increased mitochondrial quality and respiration. Then, we reconstructed the dynamic fusion-fission-mitophagy cycling of mitochondria in a computer model, integrating these processes into a single network mechanism. Both the computational model and the simulations are able to reproduce the proposed mechanism in terms of mitochondrial dynamics, levels of reactive oxygen species (ROS), mitophagy, and mitochondrial quality, thus providing a computational tool for the interpretation of the experimental data and for future studies aiming to detail further the action of NGF on mitochondrial processes. We also show that changes in these mitochondrial processes are intertwined with a metabolic function of NGF in differentiation: NGF directs a profound metabolic rearrangement involving glycolysis, TCA cycle, and the pentose phosphate pathway, altering the redox balance. This metabolic rewiring may ensure: (a) supply of both energy and building blocks for the anabolic processes needed for morphological reorganization, as well as (b) redox homeostasis.

Keywords:  NGF differentiation; computational modeling; metabolism; mitochondrial dynamics; mitophagy

DOI:  https://doi.org/10.1111/febs.17083
Mol Carcinog. 2024 Feb 14.

Glutaminase potentiates the glycolysis in esophageal squamous cell carcinoma by interacting with PDK1.

Guangzhao Zhu, Fangxia Guan, Shenglei Li, Qing Zhang, Xueying Zhang, Yue Qin, Zhangzhan Sun, Shaohua Peng, Jiexing Cheng, Yiyang Li, Ruili Ren, Tianli Fan, Hongtao Liu.

  Increasing evidence has demonstrated that glutaminase (GLS) as a key mitochondrial enzyme plays a pivotal role in glutaminolysis, which widely participates in glutamine metabolism serving as main energy sources and building blocks for tumor growth. However, the roles and molecular mechanisms of GLS in esophageal squamous cell carcinoma (ESCC) remains unknown. Here, we found that GLS was highly expressed in ESCC tissues and cells. GLS inhibitor CB-839 significantly suppressed cell proliferation, colony formation, migration and invasion of ESCC cells, whereas GLS overexpression displayed the opposite effects. In addition, CB-839 markedly suppressed glucose consumption and lactate production, coupled with the downregulation of glycolysis-related proteins HK2, PFKM, PKM2 and LDHA, whereas GLS overexpression exhibited the adverse results. In vivo animal experiment revealed that CB-839 dramatically suppressed tumor growth, whereas GLS overexpression promoted tumor growth in ESCC cells xenografted nude mice. Mechanistically, GLS was localized in mitochondria of ESCC cells, which interacted with PDK1 protein. CB-839 attenuated the interaction of GLS and PDK1 in ESCC cells by suppressing PDK1 expression, which further evoked the downregulation of p-PDHA1 (s293), however, GLS overexpression markedly enhanced the level of p-PDHA1 (s293). These findings suggest that interaction of GLS with PDK1 accelerates the glycolysis of ESCC cells by inactivating PDH enzyme, and thus targeting GLS may be a novel therapeutic approach for ESCC patients.

Keywords:  esophageal squamous cell carcinoma; glutaminase; glycolysis; pyruvate dehydrogenase E1 subunit alpha 1; pyruvate dehydrogenase kinase isoform 1

DOI:  https://doi.org/10.1002/mc.23696
Cell Rep. 2024 Feb 08. pii: S2211-1247(24)00067-6. [Epub ahead of print]43(2): 113739

GLUT1-mediated glucose import in B cells is critical for anaplerotic balance and humoral immunity.

Theresa E H Bierling, Amelie Gumann, Shannon R Ottmann, Sebastian R Schulz, Leonie Weckwerth, Jana Thomas, Arne Gessner, Magdalena Wichert, Frederic Kuwert, Franziska Rost, Manuela Hauke, Tatjana Freudenreich, Dirk Mielenz, Hans-Martin Jäck, Katharina Pracht.

  Glucose uptake increases during B cell activation and antibody-secreting cell (ASC) differentiation, but conflicting findings prevent a clear metabolic profile at different stages of B cell activation. Deletion of the glucose transporter type 1 (GLUT1) gene in mature B cells (GLUT1-cKO) results in normal B cell development, but it reduces germinal center B cells and ASCs. GLUT1-cKO mice show decreased antigen-specific antibody titers after vaccination. In vitro, GLUT1-deficient B cells show impaired activation, whereas established plasmablasts abolish glycolysis, relying on mitochondrial activity and fatty acids. Transcriptomics and metabolomics reveal an altered anaplerotic balance in GLUT1-deficient ASCs. Despite attempts to compensate for glucose deprivation by increasing mitochondrial mass and gene expression associated with glycolysis, the tricarboxylic acid cycle, and hexosamine synthesis, GLUT1-deficient ASCs lack the metabolites for energy production and mitochondrial respiration, limiting protein synthesis. We identify GLUT1 as a critical metabolic player defining the germinal center response and humoral immunity.

Keywords:  CP: Immunology; CP: Metabolism; GLUT1; adaptive immune response; antibody-secreting cell; glucose transporter type 1; glycolysis; metabolism; mitochondrial respiration; plasma cell; plasmablast

DOI:  https://doi.org/10.1016/j.celrep.2024.113739
Biogerontology. 2024 Feb 13.

Renal aging and mitochondrial quality control.

Xiuli Guo, Jiao Wang, Yinjie Wu, Xinwang Zhu, Li Xu.

  Mitochondria are dynamic organelles that participate in different cellular process that control metabolism, cell division, and survival, and the kidney is one of the most metabolically active organs that contains abundant mitochondria. Perturbations in mitochondrial homeostasis in the kidney can accelerate kidney aging, and maintaining mitochondrial homeostasis can effectively delay aging in the kidney. Kidney aging is a degenerative process linked to detrimental processes. The significance of aberrant mitochondrial homeostasis in renal aging has received increasing attention. However, the contribution of mitochondrial quality control (MQC) to renal aging has not been reviewed in detail. Here, we generalize the current factors contributing to renal aging, review the alterations in MQC during renal injury and aging, and analyze the relationship between mitochondria and intrinsic renal cells. We also introduce MQC in the context of renal aging, and discuss the study of mitochondria in the intrinsic cells of the kidney, which is the innovation of our paper. In addition, during kidney injury and repair, the specific functions and regulatory mechanisms of MQC systems in resident and circulating cell types remain unclear. Currently, most of the studies we reviewed are based on animal and cellular models, the relationship between renal tissue aging and mitochondria has not been adequately investigated in clinical studies, and there is still a long way to go.

Keywords:  Aging; Mitochondrial dysfunction; Mitochondrial quality control; Renal intrinsic cells

DOI:  https://doi.org/10.1007/s10522-023-10091-6
Cell Signal. 2024 Feb 13. pii: S0898-6568(24)00067-6. [Epub ahead of print] 111099

Ceramides and mitochondrial homeostasis.

Song Ding, Guorui Li, Tinglv Fu, Tianyu Zhang, Xiao Lu, Ning Li, Qing Geng.

  Lipotoxicity arises from the accumulation of lipid intermediates in non-adipose tissue, precipitating cellular dysfunction and death. Ceramide, a toxic byproduct of excessive free fatty acids, has been widely recognized as a primary contributor to lipotoxicity, mediating various cellular processes such as apoptosis, differentiation, senescence, migration, and adhesion. As the hub of lipid metabolism, the excessive accumulation of ceramides inevitably imposes stress on the mitochondria, leading to the disruption of mitochondrial homeostasis, which is typified by adequate ATP production, regulated oxidative stress, an optimal quantity of mitochondria, and controlled mitochondrial quality. Consequently, this review aims to collate current knowledge and facts regarding the involvement of ceramides in mitochondrial energy metabolism and quality control, thereby providing insights for future research.

Keywords:  Ceramide; ETC; Mitochondrial biogenesis; Mitochondrial dynamics; Mitophagy

DOI:  https://doi.org/10.1016/j.cellsig.2024.111099
Autophagy. 2024 Feb 15. 1-9

Did mitophagy follow the origin of mitochondria?

Mauro Degli Esposti.

  Mitophagy is the process of selective autophagy that removes superfluous and dysfunctional mitochondria. Mitophagy was first characterized in mammalian cells and is now recognized to follow several pathways including basal forms in specific organs. Mitophagy pathways are regulated by multiple, often interconnected factors. The present review aims to streamline this complexity and evaluate common elements that may define the evolutionary origin of mitophagy. Key issues surrounding mitophagy signaling at the mitochondrial surface may fundamentally derive from mitochondrial membrane dynamics. Elements of such membrane dynamics likely originated during the endosymbiosis of the alphaproteobacterial ancestor of our mitochondria but underwent an evolutionary leap forward in basal metazoa that determined the currently known variations in mitophagy signaling.Abbreviations: AGPAT, 1-acylglycerol-3-phosphate O-acyltransferase; ATG, autophagy related; BCL2L13, BCL2 like 13; BNIP3, BCL2 interacting protein 3; BNIP3L, BCL2 interacting protein 3 like; CALCOCO, calcium binding and coiled-coil domain; CL, cardiolipin; ER, endoplasmic reticulum; ERMES, ER-mitochondria encounter structure; FBXL4, F-box and leucine rich repeat protein 4; FUNDC1, FUN14 domain containing 1; GABARAPL1, GABA type A receptor associated protein like 1; HIF, hypoxia inducible factor; IMM, inner mitochondrial membrane; LBPA/BMP, lysobisphosphatidic acid; LIR, LC3-interacting region; LPA, lysophosphatidic acid; MAM, mitochondria-associated membranes; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MCL, monolysocardiolipin; ML, maximum likelihood; NBR1, NBR1 autophagy cargo receptor; OMM, outer mitochondrial membrane; PA, phosphatidic acid; PACS2, phosphofurin acidic cluster sorting protein 2; PC/PLC, phosphatidylcholine; PE, phosphatidylethanolamine; PHB2, prohibitin 2; PINK1, PTEN induced kinase 1; PtdIns, phosphatidylinositol; SAR, Stramenopiles, Apicomplexa and Rhizaria; TAX1BP1, Tax1 binding protein 1; ULK1, unc-51 like autophagy activating kinase 1; VDAC/porin, voltage dependent anion channel.

Keywords:  BNIP3; cardiolipin; evolution; membrane dynamics; mitochondria; mitophagy

DOI:  https://doi.org/10.1080/15548627.2024.2307215
Annu Rev Physiol. 2024 Feb 12. 86 149-173

Transcellular Barriers to Glucose Delivery in the Body.

Amira Klip, Katrien De Bock, Philip J Bilan, Erik A Richter.

  Glucose is the universal fuel of most mammalian cells, and it is largely replenished through dietary intake. Glucose availability to tissues is paramount for the maintenance of homeostatic energetics and, hence, supply should match demand by the consuming organs. In its journey through the body, glucose encounters cellular barriers for transit at the levels of the absorbing intestinal epithelial wall, the renal epithelium mediating glucose reabsorption, and the tight capillary endothelia (especially in the brain). Glucose transiting through these cellular barriers must escape degradation to ensure optimal glucose delivery to the bloodstream or tissues. The liver, which stores glycogen and generates glucose de novo, must similarly be able to release it intact to the circulation. We present the most up-to-date knowledge on glucose handling by the gut, liver, brain endothelium, and kidney, and discuss underlying molecular mechanisms and open questions. Diseases associated with defects in glucose delivery and homeostasis are also briefly addressed. We propose that the universal problem of sparing glucose from catabolism in favor of translocation across the barriers posed by epithelia and endothelia is resolved through common mechanisms involving glucose transfer to the endoplasmic reticulum, from where glucose exits the cells via unconventional cellular mechanisms.

Keywords:  GLUT; SLGT; endothelium; epithelium; glucose; glucose-6-phosphatase

DOI:  https://doi.org/10.1146/annurev-physiol-042022-031657
bioRxiv. 2024 Feb 04. pii: 2024.02.02.578646. [Epub ahead of print]

BRD4-mediated epigenetic regulation of endoplasmic reticulum-mitochondria contact sites is governed by the mitochondrial complex III.

Brandon Chen, Theophilus M Lynn-Nguyen, Pankaj Jadhav, Benjamin S Halligan, Nicholas J Rossiter, Rachel M Guerra, Sergei Koshkin, Imhoi Koo, Pietro Morlacchi, David A Hanna, Jason Lin, Ruma Banerjee, David J Pagliarini, Andrew D Patterson, Shyamal Mosalaganti, Jonathan Z Sexton, Tito Calì, Costas A Lyssiotis, Yatrik M Shah.

Inter-organellar communication is critical for cellular metabolic homeostasis. One of the most abundant inter-organellar interactions are those at the endoplasmic reticulum and mitochondria contact sites (ERMCS). However, a detailed understanding of the mechanisms governing ERMCS regulation and their roles in cellular metabolism are limited by a lack of tools that permit temporal induction and reversal. Through unbiased screening approaches, we identified fedratinib, an FDA-approved drug, that dramatically increases ERMCS abundance by inhibiting the epigenetic modifier BRD4. Fedratinib rapidly and reversibly modulates mitochondrial and ER morphology and alters metabolic homeostasis. Moreover, ERMCS modulation depends on mitochondria electron transport chain complex III function. Comparison of fedratinib activity to other reported inducers of ERMCS revealed common mechanisms of induction and function, providing clarity and union to a growing body of experimental observations. In total, our results uncovered a novel epigenetic signaling pathway and an endogenous metabolic regulator that connects ERMCS and cellular metabolism.

DOI: https://doi.org/10.1101/2024.02.02.578646
bioRxiv. 2024 Feb 04. pii: 2024.02.01.577463. [Epub ahead of print]

Enhancing mitochondrial pyruvate metabolism ameliorates myocardial ischemic reperfusion injury.

Joseph R Visker, Ahmad A Cluntun, Jesse N Velasco-Silva, David R Eberhardt, Thirupura S Shankar, Rana Hamouche, Jing Ling, Hyoin Kwak, Yanni Hillas, Ian Aist, Eleni Tseliou, Sutip Navankasattusas, Dipayan Chaudhuri, Gregory S Ducker, Stavros G Drakos, Jared Rutter.

The established clinical therapy for the treatment of acute myocardial infarction is primary percutaneous coronary intervention (PPCI) to restore blood flow to the ischemic myocardium. PPCI is effective at reperfusing the ischemic myocardium, however the rapid re-introduction of oxygenated blood also can cause ischemia-reperfusion (I/R) injury. Reperfusion injury is the culprit for up to half of the final myocardial damage, but there are no clinical interventions to reduce I/R injury. We previously demonstrated that inhibiting the lactate exporter, monocarboxylate transporter 4 (MCT4), and re-directing pyruvate towards oxidation can blunt isoproterenol-induced hypertrophy. Based on this finding, we hypothesized that the same pathway might be important during I/R. Here, we establish that the pyruvate-lactate metabolic axis plays a critical role in determining myocardial salvage following injury. Post-I/R injury, the mitochondrial pyruvate carrier (MPC), required for pyruvate oxidation, is upregulated in the surviving myocardium following I/R injury. MPC loss in cardiomyocytes caused more cell death with less myocardial salvage, which was associated with an upregulation of MCT4 in the myocardium at risk of injury. We deployed a pharmacological strategy of MCT4 inhibition with a highly selective compound (VB124) at the time of reperfusion. This strategy normalized reactive oxygen species (ROS), mitochondrial membrane potential (Δψ), and Ca 2+ , increased pyruvate entry to TCA cycle, and improved myocardial salvage and functional outcomes following I/R injury. Altogether, our data suggest that normalizing the pyruvate-lactate metabolic axis via MCT4 inhibition is a promising pharmacological strategy to mitigate I/R injury.GRAPHICAL ABSTRACT:

DOI: https://doi.org/10.1101/2024.02.01.577463
Mol Cell. 2024 Feb 06. pii: S1097-2765(24)00052-2. [Epub ahead of print]

The HRI branch of the integrated stress response selectively triggers mitophagy.

Yogaditya Chakrabarty, Zheng Yang, Hsiuchen Chen, David C Chan.

  To maintain mitochondrial homeostasis, damaged or excessive mitochondria are culled in coordination with the physiological state of the cell. The integrated stress response (ISR) is a signaling network that recognizes diverse cellular stresses, including mitochondrial dysfunction. Because the four ISR branches converge to common outputs, it is unclear whether mitochondrial stress detected by this network can regulate mitophagy, the autophagic degradation of mitochondria. Using a whole-genome screen, we show that the heme-regulated inhibitor (HRI) branch of the ISR selectively induces mitophagy. Activation of the HRI branch results in mitochondrial localization of phosphorylated eukaryotic initiation factor 2, which we show is sufficient to induce mitophagy. The HRI mitophagy pathway operates in parallel with the mitophagy pathway controlled by the Parkinson's disease related genes PINK1 and PARKIN and is mechanistically distinct. Therefore, HRI repurposes machinery that is normally used for translational initiation to trigger mitophagy in response to mitochondrial damage.

Keywords:  autophagy; integrated stress response; iron metabolism; mitochondria; mitophagy; organelle quality control

DOI:  https://doi.org/10.1016/j.molcel.2024.01.016
Nat Commun. 2024 Feb 16. 15(1): 1454

A system for inducible mitochondria-specific protein degradation in vivo.

Swastika Sanyal, Anna Kouznetsova, Lena Ström, Camilla Björkegren.

Targeted protein degradation systems developed for eukaryotes employ cytoplasmic machineries to perform proteolysis. This has prevented mitochondria-specific analysis of proteins that localize to multiple locations, for example, the mitochondria and the nucleus. Here, we present an inducible mitochondria-specific protein degradation system in Saccharomyces cerevisiae based on the Mesoplasma florum Lon (mf-Lon) protease and its corresponding ssrA tag (called PDT). We show that mitochondrially targeted mf-Lon protease efficiently and selectively degrades a PDT-tagged reporter protein localized to the mitochondrial matrix. The degradation can be induced by depleting adenine from the medium, and tuned by altering the promoter strength of the MF-LON gene. We furthermore demonstrate that mf-Lon specifically degrades endogenous, PDT-tagged mitochondrial proteins. Finally, we show that mf-Lon-dependent PDT degradation can also be achieved in human mitochondria. In summary, this system provides an efficient tool to selectively analyze the mitochondrial function of dually localized proteins.

DOI: https://doi.org/10.1038/s41467-024-45819-6
Nat Neurosci. 2024 Feb 15.

A neuron-glia lipid metabolic cycle couples daily sleep to mitochondrial homeostasis.

Paula R Haynes, Elana S Pyfrom, Yongjun Li, Carly Stein, Vishnu Anand Cuddapah, Jack A Jacobs, Zhifeng Yue, Amita Sehgal.

Sleep is thought to be restorative to brain energy homeostasis, but it is not clear how this is achieved. We show here that Drosophila glia exhibit a daily cycle of glial mitochondrial oxidation and lipid accumulation that is dependent on prior wake and requires the Drosophila APOE orthologs NLaz and GLaz, which mediate neuron-glia lipid transfer. In turn, a full night of sleep is required for glial lipid clearance, mitochondrial oxidative recovery and maximal neuronal mitophagy. Knockdown of neuronal NLaz causes oxidative stress to accumulate in neurons, and the neuronal mitochondrial integrity protein, Drp1, is required for daily glial lipid accumulation. These data suggest that neurons avoid accumulation of oxidative mitochondrial damage during wake by using mitophagy and passing damage to glia in the form of lipids. We propose that a mitochondrial lipid metabolic cycle between neurons and glia reflects a fundamental function of sleep relevant for brain energy homeostasis.

DOI: https://doi.org/10.1038/s41593-023-01568-1
Anal Bioanal Chem. 2024 Feb 12.

A self-immolative near-infrared fluorescent probe for identification of cancer cells and facilitating its apoptosis.

Jinlong Zhang, Taihe Han, Huipeng Sun, Zehua Han, Xuezhao Shi, Jun Gao, Xiaoyan Liu, Haixia Zhang.

  Hydrogen sulfide (H2S) plays a significant role in the onset and progression of cancer. It has led to increased interest in its potential as a diagnostic tool owing to its overexpression in cancer. However, research into the anti-cancer activity of H2S, particularly its ability to promote apoptosis, is hindered by the lack of effective detection tools. To gain a comprehensive understanding of the targeted efficacy of H2S in promoting cancer cell apoptosis, we designed and synthesized a self-immolative near-infrared fluorescent diagnostic probe, named YH-NO2. The activation of this self-immolative reaction is dependent on the presence of nitroreductase (NTR) overexpressed in tumor cells. The design of YH-NO2 involves releasing fluorophores through the activated self-immolative reaction for detection, while simultaneously releasing H2S-loaded self-immolative spacers to promote cancer cell apoptosis. Consequently, YH-NO2 achieves a seamless integration of recognizing and promoting cancer cell apoptosis through its self-immolative structure. This dual function allows YH-NO2 to recognize NTR activity in cells under varying hypoxia levels and differentiate between normal cells and cancer cells using imaging technology. Notably, YH-NO2 exhibits remarkable stability in cellular environments, providing controlled and selective H2S release, thereby targeting the elimination of cancer cells through the promotion of apoptosis. Furthermore, in vivo experiments have demonstrated that YH-NO2 can accurately identify tumor tissue and effectively reduce its size by utilizing its apoptosis-promoting properties. These findings not only provide further evidence for the anti-cancer activity of H2S but also offer valuable tools for understanding the complex relationship between H2S and cancer.

Keywords:  Apoptosis; Cancer cells; Hydrogen sulfide; In vivo imaging; Self-immolative reaction

DOI:  https://doi.org/10.1007/s00216-024-05180-5
Proc Natl Acad Sci U S A. 2024 Feb 20. 121(8): e2317343121

Cysteine induces mitochondrial reductive stress in glioblastoma through hydrogen peroxide production.

Evan K Noch, Laura Palma, Isaiah Yim, Nayah Bullen, Daniel Barnett, Alexander Walsh, Bhavneet Bhinder, Elisa Benedetti, Jan Krumsiek, Justin Gurvitch, Sumaiyah Khwaja, Daphne Atlas, Olivier Elemento, Lewis C Cantley.

  Glucose and amino acid metabolism are critical for glioblastoma (GBM) growth, but little is known about the specific metabolic alterations in GBM that are targetable with FDA-approved compounds. To investigate tumor metabolism signatures unique to GBM, we interrogated The Cancer Genome Atlas for alterations in glucose and amino acid signatures in GBM relative to other human cancers and found that GBM exhibits the highest levels of cysteine and methionine pathway gene expression of 32 human cancers. Treatment of patient-derived GBM cells with the FDA-approved single cysteine compound N-acetylcysteine (NAC) reduced GBM cell growth and mitochondrial oxygen consumption, which was worsened by glucose starvation. Normal brain cells and other cancer cells showed no response to NAC. Mechanistic experiments revealed that cysteine compounds induce rapid mitochondrial H2O2 production and reductive stress in GBM cells, an effect blocked by oxidized glutathione, thioredoxin, and redox enzyme overexpression. From analysis of the clinical proteomic tumor analysis consortium (CPTAC) database, we found that GBM cells exhibit lower expression of mitochondrial redox enzymes than four other cancers whose proteomic data are available in CPTAC. Knockdown of mitochondrial thioredoxin-2 in lung cancer cells induced NAC susceptibility, indicating the importance of mitochondrial redox enzyme expression in mitigating reductive stress. Intraperitoneal treatment of mice bearing orthotopic GBM xenografts with a two-cysteine peptide induced H2O2 in brain tumors in vivo. These findings indicate that GBM is uniquely susceptible to NAC-driven reductive stress and could synergize with glucose-lowering treatments for GBM.

Keywords:  cysteine; glioblastoma; hydrogen peroxide; mitochondrial metabolism; reductive stress

DOI:  https://doi.org/10.1073/pnas.2317343121
Cell. 2024 Feb 08. pii: S0092-8674(24)00067-9. [Epub ahead of print]

Phospholipids with two polyunsaturated fatty acyl tails promote ferroptosis.

Baiyu Qiu, Fereshteh Zandkarimi, Carla T Bezjian, Eduard Reznik, Rajesh Kumar Soni, Wei Gu, Xuejun Jiang, Brent R Stockwell.

  Phospholipids containing a single polyunsaturated fatty acyl tail (PL-PUFA1s) are considered the driving force behind ferroptosis, whereas phospholipids with diacyl-PUFA tails (PL-PUFA2s) have been rarely characterized. Dietary lipids modulate ferroptosis, but the mechanisms governing lipid metabolism and ferroptosis sensitivity are not well understood. Our research revealed a significant accumulation of diacyl-PUFA phosphatidylcholines (PC-PUFA2s) following fatty acid or phospholipid treatments, correlating with cancer cell sensitivity to ferroptosis. Depletion of PC-PUFA2s occurred in aging and Huntington's disease brain tissue, linking it to ferroptosis. Notably, PC-PUFA2s interacted with the mitochondrial electron transport chain, generating reactive oxygen species (ROS) for initiating lipid peroxidation. Mitochondria-targeted antioxidants protected cells from PC-PUFA2-induced mitochondrial ROS (mtROS), lipid peroxidation, and cell death. These findings reveal a critical role for PC-PUFA2s in controlling mitochondria homeostasis and ferroptosis in various contexts and explain the ferroptosis-modulating mechanisms of free fatty acids. PC-PUFA2s may serve as diagnostic and therapeutic targets for modulating ferroptosis.

Keywords:  PUFA; ROS; complex I; diacyl-PUFA phosphatidylcholine; electron transport chain; ferroptosis; lipids; mitochondria; phospholipid; polyunsaturated fatty acid

DOI:  https://doi.org/10.1016/j.cell.2024.01.030
EMBO J. 2024 Feb 15.

VHL suppresses autophagy and tumor growth through PHD1-dependent Beclin1 hydroxylation.

Zheng Wang, Meisi Yan, Leiguang Ye, Qimin Zhou, Yuran Duan, Hongfei Jiang, Lei Wang, Yuan Ouyang, Huahe Zhang, Yuli Shen, Guimei Ji, Xiaohan Chen, Qi Tian, Liwei Xiao, Qingang Wu, Ying Meng, Guijun Liu, Leina Ma, Bo Lei, Zhimin Lu, Daqian Xu.

  The Von Hippel-Lindau (VHL) protein, which is frequently mutated in clear-cell renal cell carcinoma (ccRCC), is a master regulator of hypoxia-inducible factor (HIF) that is involved in oxidative stresses. However, whether VHL possesses HIF-independent tumor-suppressing activity remains largely unclear. Here, we demonstrate that VHL suppresses nutrient stress-induced autophagy, and its deficiency in sporadic ccRCC specimens is linked to substantially elevated levels of autophagy and correlates with poorer patient prognosis. Mechanistically, VHL directly binds to the autophagy regulator Beclin1, after its PHD1-mediated hydroxylation on Pro54. This binding inhibits the association of Beclin1-VPS34 complexes with ATG14L, thereby inhibiting autophagy initiation in response to nutrient deficiency. Expression of non-hydroxylatable Beclin1 P54A abrogates VHL-mediated autophagy inhibition and significantly reduces the tumor-suppressing effect of VHL. In addition, Beclin1 P54-OH levels are inversely correlated with autophagy levels in wild-type VHL-expressing human ccRCC specimens, and with poor patient prognosis. Furthermore, combined treatment of VHL-deficient mouse tumors with autophagy inhibitors and HIF2α inhibitors suppresses tumor growth. These findings reveal an unexpected mechanism by which VHL suppresses tumor growth, and suggest a potential treatment for ccRCC through combined inhibition of both autophagy and HIF2α.

Keywords:  Autophagy; Beclin1; Hydroxylation; VHL; ccRCC

DOI:  https://doi.org/10.1038/s44318-024-00051-2
Nat Struct Mol Biol. 2024 Feb 12.

Single-nucleoid architecture reveals heterogeneous packaging of mitochondrial DNA.

R Stefan Isaac, Thomas W Tullius, Katja G Hansen, Danilo Dubocanin, Mary Couvillion, Andrew B Stergachis, L Stirling Churchman.

Cellular metabolism relies on the regulation and maintenance of mitochondrial DNA (mtDNA). Hundreds to thousands of copies of mtDNA exist in each cell, yet because mitochondria lack histones or other machinery important for nuclear genome compaction, it remains unresolved how mtDNA is packaged into individual nucleoids. In this study, we used long-read single-molecule accessibility mapping to measure the compaction of individual full-length mtDNA molecules at near single-nucleotide resolution. We found that, unlike the nuclear genome, human mtDNA largely undergoes all-or-none global compaction, with most nucleoids existing in an inaccessible, inactive state. Highly accessible mitochondrial nucleoids are co-occupied by transcription and replication components and selectively form a triple-stranded displacement loop structure. In addition, we showed that the primary nucleoid-associated protein TFAM directly modulates the fraction of inaccessible nucleoids both in vivo and in vitro, acting consistently with a nucleation-and-spreading mechanism to coat and compact mitochondrial nucleoids. Together, these findings reveal the primary architecture of mtDNA packaging and regulation in human cells.

DOI: https://doi.org/10.1038/s41594-024-01225-6
Nat Rev Mol Cell Biol. 2024 Feb 14.

Mechanisms and functions of protein S-acylation.

Francisco S Mesquita, Laurence Abrami, Maurine E Linder, Shernaz X Bamji, Bryan C Dickinson, F Gisou van der Goot.

Over the past two decades, protein S-acylation (often referred to as S-palmitoylation) has emerged as an important regulator of vital signalling pathways. S-Acylation is a reversible post-translational modification that involves the attachment of a fatty acid to a protein. Maintenance of the equilibrium between protein S-acylation and deacylation has demonstrated profound effects on various cellular processes, including innate immunity, inflammation, glucose metabolism and fat metabolism, as well as on brain and heart function. This Review provides an overview of current understanding of S-acylation and deacylation enzymes, their spatiotemporal regulation by sophisticated multilayered mechanisms, and their influence on protein function, cellular processes and physiological pathways. Furthermore, we examine how disruptions in protein S-acylation are associated with a broad spectrum of diseases from cancer to autoinflammatory disorders and neurological conditions.

DOI: https://doi.org/10.1038/s41580-024-00700-8
iScience. 2024 Mar 15. 27(3): 108959

Metabolic rewiring and autophagy inhibition correct lysosomal storage disease in mucopolysaccharidosis IIIB.

Melania Scarcella, Gianluca Scerra, Mariangela Ciampa, Marianna Caterino, Michele Costanzo, Laura Rinaldi, Antonio Feliciello, Serenella Anzilotti, Chiara Fiorentino, Maurizio Renna, Margherita Ruoppolo, Luigi Michele Pavone, Massimo D'Agostino, Valeria De Pasquale.

  Mucopolysaccharidoses (MPSs) are lysosomal disorders with neurological involvement for which no cure exists. Here, we show that recombinant NK1 fragment of hepatocyte growth factor rescues substrate accumulation and lysosomal defects in MPS I, IIIA and IIIB patient fibroblasts. We investigated PI3K/Akt pathway, which is of crucial importance for neuronal function and survival, and demonstrate that PI3K inhibition abolishes NK1 therapeutic effects. We identified that autophagy inhibition, by Beclin1 silencing, reduces MPS IIIB phenotype and that NK1 downregulates autophagic-lysosome (ALP) gene expression, suggesting a possible contribution of autophagosome biogenesis in MPS. Indeed, metabolomic analyses revealed defects of mitochondrial activity accompanied by anaerobic metabolism and inhibition of AMP-activated protein kinase (AMPK), which acts on metabolism and autophagy, rescues lysosomal defects. These results provide insights into the molecular mechanisms of MPS IIIB physiopathology, supporting the development of new promising approaches based on autophagy inhibition and metabolic rewiring to correct lysosomal pathology in MPSs.

Keywords:  Cell biology; Human metabolism

DOI:  https://doi.org/10.1016/j.isci.2024.108959
Cancer Res. 2024 Feb 16.

Decoding Serine Metabolism: Unveiling Novel Pathways for Evolving Cancer Therapies.

Aristotle Lau, John Blenis, Guillermo Burgos-Barragan.

Serine metabolism plays a pivotal role in cancer, making it an appealing therapeutic target. Two recent studies published in Nature Metabolism and Science Translational Medicine uncovered novel players and therapeutic opportunities within this crucial metabolic pathway. Papalazarou and colleagues employed genetic tools coupled with metabolomics and high-throughput imaging to identify and characterize membrane transporters involved in serine uptake and mitochondrial import in colorectal cancer. Notably, they showed that dual inhibition of these transporters in combination with impaired serine biosynthesis reduced tumor growth in xenograft models. In a parallel study, Zhang and colleagues identified isocitrate dehydrogenase I (IDH1) as a novel regulator of serine biosynthesis in non-small cell lung cancer (NSCLC). Through extensive mechanistic studies, they demonstrated that IDH1 enhances the expression of the key enzymes phosphoglycerate dehydrogenase (PHGDH) and phosphoserine aminotransferase 1 (PSAT1) via a non-canonical function independent of its enzymatic activity. Strikingly, pharmacological disruption of this novel function of IDH1 not only diminished tumor growth but also enhanced the anticancer efficacy of dietary serine restriction in mouse models of lung cancer. Together, these studies advance our mechanistic understanding of how cancer cells fulfill their serine requirements and reveal innovative therapeutic avenues to deprive tumors of this vital nutrient.

DOI: https://doi.org/10.1158/0008-5472.CAN-24-0541
Nat Genet. 2024 Feb 15.

Multi-omic profiling of clear cell renal cell carcinoma identifies metabolic reprogramming associated with disease progression.

Junyi Hu, Shao-Gang Wang, Yaxin Hou, Zhaohui Chen, Lilong Liu, Ruizhi Li, Nisha Li, Lijie Zhou, Yu Yang, Liping Wang, Liang Wang, Xiong Yang, Yichen Lei, Changqi Deng, Yang Li, Zhiyao Deng, Yuhong Ding, Yingchun Kuang, Zhipeng Yao, Yang Xun, Fan Li, Heng Li, Jia Hu, Zheng Liu, Tao Wang, Yi Hao, Xuanmao Jiao, Wei Guan, Zhen Tao, Shancheng Ren, Ke Chen.

Clear cell renal cell carcinoma (ccRCC) is a complex disease with remarkable immune and metabolic heterogeneity. Here we perform genomic, transcriptomic, proteomic, metabolomic and spatial transcriptomic and metabolomic analyses on 100 patients with ccRCC from the Tongji Hospital RCC (TJ-RCC) cohort. Our analysis identifies four ccRCC subtypes including De-clear cell differentiated (DCCD)-ccRCC, a subtype with distinctive metabolic features. DCCD cancer cells are characterized by fewer lipid droplets, reduced metabolic activity, enhanced nutrient uptake capability and a high proliferation rate, leading to poor prognosis. Using single-cell and spatial trajectory analysis, we demonstrate that DCCD is a common mode of ccRCC progression. Even among stage I patients, DCCD is associated with worse outcomes and higher recurrence rate, suggesting that it cannot be cured by nephrectomy alone. Our study also suggests a treatment strategy based on subtype-specific immune cell infiltration that could guide the clinical management of ccRCC.

DOI: https://doi.org/10.1038/s41588-024-01662-5
Nat Commun. 2024 Feb 13. 15(1): 1328

Structural basis for regulated assembly of the mitochondrial fission GTPase Drp1.

Kristy Rochon, Brianna L Bauer, Nathaniel A Roethler, Yuli Buckley, Chih-Chia Su, Wei Huang, Rajesh Ramachandran, Maria S K Stoll, Edward W Yu, Derek J Taylor, Jason A Mears.

Mitochondrial fission is a critical cellular event to maintain organelle function. This multistep process is initiated by the enhanced recruitment and oligomerization of dynamin-related protein 1 (Drp1) at the surface of mitochondria. As such, Drp1 is essential for inducing mitochondrial division in mammalian cells, and homologous proteins are found in all eukaryotes. As a member of the dynamin superfamily of proteins (DSPs), controlled Drp1 self-assembly into large helical polymers stimulates its GTPase activity to promote membrane constriction. Still, little is known about the mechanisms that regulate correct spatial and temporal assembly of the fission machinery. Here we present a cryo-EM structure of a full-length Drp1 dimer in an auto-inhibited state. This dimer reveals two key conformational rearrangements that must be unlocked through intramolecular rearrangements to achieve the assembly-competent state observed in previous structures. This structural insight provides understanding into the mechanism for regulated self-assembly of the mitochondrial fission machinery.

DOI: https://doi.org/10.1038/s41467-024-45524-4
Cell Rep. 2024 Feb 12. pii: S2211-1247(24)00066-4. [Epub ahead of print]43(2): 113738

Proline restores mitochondrial function and reverses aging hallmarks in senescent cells.

Debanik Choudhury, Na Rong, Hamsa Vardini Senthil Kumar, Sydney Swedick, Ronel Z Samuel, Pihu Mehrotra, John Toftegaard, Nika Rajabian, Ramkumar Thiyagarajan, Ashis K Podder, Yulun Wu, Shahryar Shahini, Kenneth L Seldeen, Bruce Troen, Pedro Lei, Stelios T Andreadis.

  Mitochondrial dysfunction is a hallmark of cellular senescence, with the loss of mitochondrial function identified as a potential causal factor contributing to senescence-associated decline in cellular functions. Our recent findings revealed that ectopic expression of the pluripotency transcription factor NANOG rejuvenates dysfunctional mitochondria of senescent cells by rewiring metabolic pathways. In this study, we report that NANOG restores the expression of key enzymes, PYCR1 and PYCR2, in the proline biosynthesis pathway. Additionally, senescent mesenchymal stem cells manifest severe mitochondrial respiratory impairment, which is alleviated through proline supplementation. Proline induces mitophagy by activating AMP-activated protein kinase α and upregulating Parkin expression, enhancing mitochondrial clearance and ultimately restoring cell metabolism. Notably, proline treatment also mitigates several aging hallmarks, including DNA damage, senescence-associated β-galactosidase, inflammatory cytokine expressions, and impaired myogenic differentiation capacity. Overall, this study highlights the role of proline in mitophagy and its potential in reversing senescence-associated mitochondrial dysfunction and aging hallmarks.

Keywords:  AMPKα; CP: Cell biology; CP: Metabolism; Parkin; aging; amino acid; autophagy; mitochondria; mitophagy; proline; senescence

DOI:  https://doi.org/10.1016/j.celrep.2024.113738
Sci Adv. 2024 Feb 16. 10(7): eadk2317

A mechanism of lysosomal calcium entry.

Matthew Zajac, Sourajit Mukherjee, Palapuravan Anees, Daphne Oettinger, Katharine Henn, Jainaha Srikumar, Junyi Zou, Anand Saminathan, Yamuna Krishnan.

Lysosomal calcium (Ca2+) release is critical to cell signaling and is mediated by well-known lysosomal Ca2+ channels. Yet, how lysosomes refill their Ca2+ remains hitherto undescribed. Here, from an RNA interference screen in Caenorhabditis elegans, we identify an evolutionarily conserved gene, lci-1, that facilitates lysosomal Ca2+ entry in C. elegans and mammalian cells. We found that its human homolog TMEM165, previously designated as a Ca2+/H+ exchanger, imports Ca2+ pH dependently into lysosomes. Using two-ion mapping and electrophysiology, we show that TMEM165, hereafter referred to as human LCI, acts as a proton-activated, lysosomal Ca2+ importer. Defects in lysosomal Ca2+ channels cause several neurodegenerative diseases, and knowledge of lysosomal Ca2+ importers may provide previously unidentified avenues to explore the physiology of Ca2+ channels.

DOI: https://doi.org/10.1126/sciadv.adk2317
Ageing Res Rev. 2024 Feb 13. pii: S1568-1637(24)00051-5. [Epub ahead of print] 102233

Role of ketogenic diet in neurodegenerative diseases focusing on Alzheimer diseases: The guardian angle.

Hayder M Al-Kuraishy, Majid S Jabir, Ali K Albuhadily, Ali I Al-Gareeb, Sabrean F Jawad, Ayman A Swelum, Najah R Hadi.

  The ketogenic diet (KD) is a low-carbohydrate, adequate protein and high-fat diet. KD is primarily used to treat refractory epilepsy. KD was shown to be effective in treating different neurodegenerative diseases. Alzheimer disease (AD) is the first common neurodegenerative disease in the world characterized by memory and cognitive impairment. However, the underlying mechanism of KD in controlling of AD and other neurodegenerative diseases are not discussed widely. Therefore, this review aims to revise the fundamental mechanism of KD in different neurodegenerative diseases focusing on the AD. KD induces a fasting-like which modulates the central and peripheral metabolism by regulating mitochondrial dysfunction, oxidative stress, inflammation, gut-flora, and autophagy in different neurodegenerative diseases. Different studies highlighted that KD improves AD neuropathology by regulating synaptic neurotransmission and inhibiting of neuroinflammation and oxidative stress. In conclusion, KD improves cognitive function and attenuates the progression of AD neuropathology by reducing oxidative stress, mitochondrial dysfunction, and enhancing neuronal autophagy and brain BDNF.

Keywords:  Alzheimer disease; ketogenic diet; neurodegenerative diseases

DOI:  https://doi.org/10.1016/j.arr.2024.102233
Cell Metab. 2024 Feb 13. pii: S1550-4131(24)00013-5. [Epub ahead of print]

SLC25A51 decouples the mitochondrial NAD+/NADH ratio to control proliferation of AML cells.

Mu-Jie Lu, Jonathan Busquets, Valeria Impedovo, Crystal N Wilson, Hsin-Ru Chan, Yu-Tai Chang, William Matsui, Stefano Tiziani, Xiaolu A Cambronne.

  SLC25A51 selectively imports oxidized NAD+ into the mitochondrial matrix and is required for sustaining cell respiration. We observed elevated expression of SLC25A51 that correlated with poorer outcomes in patients with acute myeloid leukemia (AML), and we sought to determine the role SLC25A51 may serve in this disease. We found that lowering SLC25A51 levels led to increased apoptosis and prolonged survival in orthotopic xenograft models. Metabolic flux analyses indicated that depletion of SLC25A51 shunted flux away from mitochondrial oxidative pathways, notably without increased glycolytic flux. Depletion of SLC25A51 combined with 5-azacytidine treatment limits expansion of AML cells in vivo. Together, the data indicate that AML cells upregulate SLC25A51 to decouple mitochondrial NAD+/NADH for a proliferative advantage by supporting oxidative reactions from a variety of fuels. Thus, SLC25A51 represents a critical regulator that can be exploited by cancer cells and may be a vulnerability for refractory AML.

Keywords:  AML; MCART1; SLC25A51; glutamine utilization; oxidative mitochondria; tumor metabolism

DOI:  https://doi.org/10.1016/j.cmet.2024.01.013
Nat Commun. 2024 Feb 16. 15(1): 1442

Hijacking of nucleotide biosynthesis and deamidation-mediated glycolysis by an oncogenic herpesvirus.

Quanyuan Wan, Leah Tavakoli, Ting-Yu Wang, Andrew J Tucker, Ruiting Zhou, Qizhi Liu, Shu Feng, Dongwon Choi, Zhiheng He, Michaela U Gack, Jun Zhao.

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS) and multiple types of B cell malignancies. Emerging evidence demonstrates that KSHV reprograms host-cell central carbon metabolic pathways, which contributes to viral persistence and tumorigenesis. However, the mechanisms underlying KSHV-mediated metabolic reprogramming remain poorly understood. Carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase (CAD) is a key enzyme of the de novo pyrimidine synthesis, and was recently identified to deamidate the NF-κB subunit RelA to promote aerobic glycolysis and cell proliferation. Here we report that KSHV infection exploits CAD for nucleotide synthesis and glycolysis. Mechanistically, KSHV vCyclin binds to and hijacks cyclin-dependent kinase CDK6 to phosphorylate Ser-1900 on CAD, thereby activating CAD-mediated pyrimidine synthesis and RelA-deamidation-mediated glycolytic reprogramming. Correspondingly, genetic depletion or pharmacological inhibition of CDK6 and CAD potently impeded KSHV lytic replication and thwarted tumorigenesis of primary effusion lymphoma (PEL) cells in vitro and in vivo. Altogether, our work defines a viral metabolic reprogramming mechanism underpinning KSHV oncogenesis, which may spur the development of new strategies to treat KSHV-associated malignancies and other diseases.

DOI: https://doi.org/10.1038/s41467-024-45852-5