bims-micesi 2024-06-23 papers

bims-micesi

Biomed News

on Mitotic cell signalling

Issue of 2024–06–23
fourteen papers selected by
Valentina Piano, Uniklinik Köln

The CCTδ subunit of the molecular chaperone CCT is required for correct localisation of p150Glued to spindle poles during mitosis.
Mechanics of spindle orientation in human mitotic cells is determined by pulling forces on astral microtubules and clustering of cortical dynein.
CYR61 Acts as an Intracellular Microtubule-Associated Protein and Coordinates Mitotic Progression via PLK1-FBW7 Pathway.
Mitotic kinases are emerging therapeutic targets against metastatic breast cancer.
Kinesin motor KIF16A regulates microtubule stability and actin-dependent spindle migration in mouse oocyte meiosis.
Pharmacological inhibition of protein kinase D2/Aurora kinase A signalling axis suppresses G2/M cell cycle progression and proliferation of epithelial ovarian cancer cells.
The non-mitotic role of HMMR in regulating the localization of TPX2 and the dynamics of microtubules in neurons.
A phosphorylation-controlled switch confers cell cycle-dependent protein relocalization.
Tight Junction Component Occludin Binds to FIP5 to Regulate Endosome Trafficking and Mitotic Spindle Function.
Chromosome segregation: Brushing up on centromeres.
Greatwall-Endos-PP2A/B55Twins network regulates translation and stability of maternal transcripts in the Drosophila oocyte-to-embryo transition.
USP11 modulates mitotic progression and senescence by regulating the p53-p21 axis through MDM2 deubiquitination.
The chromatin-associated 53BP1 ortholog, HSR-9, regulates recombinational repair and X chromosome segregation in the Caenorhabditis elegans germ line.
Phosphorylation of Orc6 During Mitosis Regulates DNA Replication and Ribosome Biogenesis.

Eur J Cell Biol. 2024 Jun 15. pii: S0171-9335(24)00047-5. [Epub ahead of print]103(3): 151430

The CCTδ subunit of the molecular chaperone CCT is required for correct localisation of p150Glued to spindle poles during mitosis.

Carmen M Córdoba-Beldad, Julie Grantham.

  Chaperonin Containing Tailless complex polypeptide 1 (CCT) is a molecular chaperone composed of eight distinct subunits that can exist as individual monomers or as components of a double oligomeric ring, which is essential for the folding of actin and tubulin and other substrates. Here we assess the role of CCT subunits in the context of cell cycle progression by individual subunit depletions upon siRNA treatment in mammalian cells. The depletion of individual CCT subunits leads to variation in the distribution of cell cycle phases and changes in mitotic index. Mitotic defects, such as unaligned chromosomes occur when CCTδ is depleted, concurrent with a reduction in spindle pole-localised p150Glued, a component of the dynactin complex and a binding partner of monomeric CCTδ. In CCTδ-depleted cells, changes in the elution profile of p150Glued are observed consistent with altered conformations and or assembly states with the dynactin complex. Addition of monomeric CCTδ, in the form of GFP-CCTδ, restores correct p150Glued localisation to the spindle poles and rescues the mitotic segregation defects that occur when CCTδ is depleted. This study demonstrates a requirement for CCTδ in its monomeric form for correct chromosome segregation via a mechanism that promotes the correct localisation of p150Glued, thus revealing further complexities to the interplay between CCT, tubulin folding and microtubule dynamics.

Keywords:  Cell division; Chaperonin; Chromosome segregation; Dynein/dynactin; TRiC

DOI:  https://doi.org/10.1016/j.ejcb.2024.151430
Dev Cell. 2024 Jun 04. pii: S1534-5807(24)00340-X. [Epub ahead of print]

Mechanics of spindle orientation in human mitotic cells is determined by pulling forces on astral microtubules and clustering of cortical dynein.

Maya I Anjur-Dietrich, Vicente Gomez Hererra, Reza Farhadifar, Haiyin Wu, Holly Merta, Shirin Bahmanyar, Michael J Shelley, Daniel J Needleman.

  The forces that orient the spindle in human cells remain poorly understood due to a lack of direct mechanical measurements in mammalian systems. We use magnetic tweezers to measure the force on human mitotic spindles. Combining the spindle's measured resistance to rotation, the speed at which it rotates after laser ablating astral microtubules, and estimates of the number of ablated microtubules reveals that each microtubule contacting the cell cortex is subject to ∼5 pN of pulling force, suggesting that each is pulled on by an individual dynein motor. We find that the concentration of dynein at the cell cortex and extent of dynein clustering are key determinants of the spindle's resistance to rotation, with little contribution from cytoplasmic viscosity, which we explain using a biophysically based mathematical model. This work reveals how pulling forces on astral microtubules determine the mechanics of spindle orientation and demonstrates the central role of cortical dynein clustering.

Keywords:  clustering; dynein; forces; mechanics; metaphase; microtubules; mitosis; orientation; spindle

DOI:  https://doi.org/10.1016/j.devcel.2024.05.022
Int J Biol Sci. 2024 ;20(8): 3140-3155

CYR61 Acts as an Intracellular Microtubule-Associated Protein and Coordinates Mitotic Progression via PLK1-FBW7 Pathway.

Kaishun Hu, Limin Xie, Wenjing Wu, Jingyuan Zhang, Yu Li, Jiehua He, Yin Zhang, Daning Lu, H Phillip Koeffler, Lehang Lin, Dong Yin.

  Cysteine-rich angiogenic inducer 61 (CYR61), also called CCN1, has long been characterized as a secretory protein. Nevertheless, the intracellular function of CYR61 remains unclear. Here, we found that CYR61 is important for proper cell cycle progression. Specifically, CYR61 interacts with microtubules and promotes microtubule polymerization to ensure mitotic entry. Moreover, CYR61 interacts with PLK1 and accumulates during the mitotic process, followed by degradation as mitosis concludes. The proteolysis of CYR61 requires the PLK1 kinase activity, which directly phosphorylates two conserved motifs on CYR61, enhancing its interaction with the SCF E3 complex subunit FBW7 and mediating its degradation by the proteasome. Mutations of phosphorylation sites of Ser167 and Ser188 greatly increase CYR61's stability, while deletion of CYR61 extends prophase and metaphase and delays anaphase onset. In summary, our findings highlight the precise control of the intracellular CYR61 by the PLK1-FBW7 pathway, accentuating its significance as a microtubule-associated protein during mitotic progression.

Keywords:  CYR61; FBW7; PLK1; microtubules; mitosis

DOI:  https://doi.org/10.7150/ijbs.93335
Cell Div. 2024 Jun 17. 19(1): 21

Mitotic kinases are emerging therapeutic targets against metastatic breast cancer.

Alexandra N Aquino-Acevedo, Joel A Orengo-Orengo, Melanie E Cruz-Robles, Harold I Saavedra.

  This review aims to outline mitotic kinase inhibitors' roles as potential therapeutic targets and assess their suitability as a stand-alone clinical therapy or in combination with standard treatments for advanced-stage solid tumors, including triple-negative breast cancer (TNBC). Breast cancer poses a significant global health risk, with TNBC standing out as the most aggressive subtype. Comprehending the role of mitosis is crucial for understanding how TNBC advances from a solid tumor to metastasis. Chemotherapy is the primary treatment used to treat TNBC. Some types of chemotherapeutic agents target cells in mitosis, thus highlighting the need to comprehend the molecular mechanisms governing mitosis in cancer. This understanding is essential for devising targeted therapies to disrupt these mitotic processes, prevent or treat metastasis, and improve patient outcomes. Mitotic kinases like Aurora kinase A, Aurora Kinase B, never in mitosis gene A-related kinase 2, Threonine-Tyrosine kinase, and Polo-kinase 1 significantly impact cell cycle progression by contributing to chromosome separation and centrosome homeostasis. When these kinases go awry, they can trigger chromosome instability, increase cell proliferation, and activate different molecular pathways that culminate in a transition from epithelial to mesenchymal cells. Ongoing clinical trials investigate various mitotic kinase inhibitors as potential biological treatments against advanced solid tumors. While clinical trials against mitotic kinases have shown some promise in the clinic, more investigation is necessary, since they induce severe adverse effects, particularly affecting the hematopoietic system.

Keywords:  Aurora kinases a and B; Centrosome; Mitosis; Mitotic kinase inhibitors; NEK2; PLK1; TTK; The spindle assembly checkpoint; Triple-negative breast cancer

DOI:  https://doi.org/10.1186/s13008-024-00125-x
FASEB J. 2024 Jul 15. 38(13): e23750

Kinesin motor KIF16A regulates microtubule stability and actin-dependent spindle migration in mouse oocyte meiosis.

Wei Wang, Zhenhu Shi, Dandan Zhang, Wenwen Hou, Huijie Ma, Xinyu Liu, Yongteng Zhang, Jinbao Zhu, Zaishan Yang, Bo Jia, Qimei Xu, Yunhai Zhang, Mianqun Zhang.

  Kif16A, a member of the kinesin-3 family of motor proteins, has been shown to play crucial roles in inducing mitotic arrest, apoptosis, and mitotic cell death. However, its roles during oocyte meiotic maturation have not been fully defined. In this study, we report that Kif16A exhibits unique accumulation on the spindle apparatus and colocalizes with microtubule fibers during mouse oocyte meiotic maturation. Targeted depletion of Kif16A using gene-targeting siRNA disrupts the progression of the meiotic cell cycle. Furthermore, Kif16A depletion leads to aberrant spindle assembly and chromosome misalignment in oocytes. Our findings also indicate that Kif16A depletion reduces tubulin acetylation levels and compromises microtubule resistance to depolymerizing drugs, suggesting its crucial role in microtubule stability maintenance. Notably, we find that the depletion of Kif16A results in a notably elevated incidence of defective kinetochore-microtubule attachments and the absence of BubR1 localization at kinetochores, suggesting a critical role for Kif16A in the activation of the spindle assembly checkpoint (SAC) activity. Additionally, we observe that Kif16A is indispensable for proper actin filament distribution, thereby impacting spindle migration. In summary, our findings demonstrate that Kif16A plays a pivotal role in regulating microtubule and actin dynamics crucial for ensuring both spindle assembly and migration during mouse oocyte meiotic maturation.

Keywords:  KIF16A; kinetochore‐microtubule attachment; oocyte meiosis; spindle assembly; spindle migration

DOI:  https://doi.org/10.1096/fj.202400989R
Pathol Res Pract. 2024 Jun 12. pii: S0344-0338(24)00301-7. [Epub ahead of print]260 155390

Pharmacological inhibition of protein kinase D2/Aurora kinase A signalling axis suppresses G2/M cell cycle progression and proliferation of epithelial ovarian cancer cells.

Abha Sachdeva, Adhiraj Roy, Manoj Kumar Gupta, Supratim Mandal.

  Epithelial ovarian cancer (EOC) is the deadliest gynecological malignancy with poor prognosis and patient survival outcome. Protein kinase D2 (PKD2) belongs to Ca++/calmodulin-dependent serine/threonine kinase family and its aberrant expression is associated with many cellular and physiological functions associated with tumorigenesis including cell proliferation. We show that PKD2 is activated during G2/M cell cycle transition and its catalytic inactivation by small molecule inhibitor CRT0066101 or genetic knockdown caused suppression of EOC cell proliferation followed by a delay into mitotic entry. Our RNASeq analysis of PKD2-inactivated EOC cells revealed significant downregulation of genes associated with cell cycle including Aurora kinase A, a critical mitotic regulator. Mechanistically, PKD2 positively regulated Aurora kinase A stability at both transcriptional and post-translational levels by interfering with the function of Fbxw7, drove G2/M cell cycle transition and EOC cell proliferation. Moreover, pharmacological inhibition of Aurora kinase A by small molecule CD532 or its shRNA-mediated genetic knockdown suppressed EOC cell proliferation, induced G2/M cell cycle arrest and mitotic catastrophe followed by apoptosis. Taken together, our results indicated that PKD2 positively regulates Aurora kinase A during G2/M cell cycle entry and pharmacological targeting of PKD2/Aurora kinase A signalling axis could serve as a novel therapeutic intervention against a lethal pathology like EOC.

Keywords:  Aurora kinase A; Cancer therapeutics; Cell cycle; Epithelial ovarian cancer; Protein kinase D2

DOI:  https://doi.org/10.1016/j.prp.2024.155390
Elife. 2024 Jun 21. pii: RP94547. [Epub ahead of print]13

The non-mitotic role of HMMR in regulating the localization of TPX2 and the dynamics of microtubules in neurons.

Yi-Ju Chen, Shun-Cheng Tseng, Peng-Tzu Chen, Eric Hwang.

  A functional nervous system is built upon the proper morphogenesis of neurons to establish the intricate connection between them. The microtubule cytoskeleton is known to play various essential roles in this morphogenetic process. While many microtubule-associated proteins (MAPs) have been demonstrated to participate in neuronal morphogenesis, the function of many more remains to be determined. This study focuses on a MAP called HMMR in mice, which was originally identified as a hyaluronan binding protein and later found to possess microtubule and centrosome binding capacity. HMMR exhibits high abundance on neuronal microtubules and altering the level of HMMR significantly affects the morphology of neurons. Instead of confining to the centrosome(s) like cells in mitosis, HMMR localizes to microtubules along axons and dendrites. Furthermore, transiently expressing HMMR enhances the stability of neuronal microtubules and increases the formation frequency of growing microtubules along the neurites. HMMR regulates the microtubule localization of a non-centrosomal microtubule nucleator TPX2 along the neurite, offering an explanation for how HMMR contributes to the promotion of growing microtubules. This study sheds light on how cells utilize proteins involved in mitosis for non-mitotic functions.

Keywords:  +tips; branching; cell biology; mouse; nucleation; outgrowth

DOI:  https://doi.org/10.7554/eLife.94547
bioRxiv. 2024 Jun 06. pii: 2024.06.05.597552. [Epub ahead of print]

A phosphorylation-controlled switch confers cell cycle-dependent protein relocalization.

Xiaofu Cao, Shiying Huang, Mateusz M Wagner, Yuan-Ting Cho, Din-Chi Chiu, Krista M Wartchow, Artur Lazarian, Laura Beth McIntire, Marcus B Smolka, Jeremy M Baskin.

Tools for acute manipulation of protein localization enable elucidation of spatiotemporally defined functions, but their reliance on exogenous triggers can interfere with cell physiology. This limitation is particularly apparent for studying mitosis, whose highly choreographed events are sensitive to perturbations. Here we exploit the serendipitous discovery of a phosphorylation-controlled, cell cycle-dependent localization change of the adaptor protein PLEKHA5 to develop a system for mitosis-specific protein recruitment to the plasma membrane that requires no exogenous stimulus. Mitosis-enabled Anchor-away/Recruiter System (MARS) comprises an engineered, 15-kDa module derived from PLEKHA5 capable of recruiting functional protein cargoes to the plasma membrane during mitosis, either through direct fusion or via GFP-GFP nanobody interaction. Applications of MARS include both knock sideways to rapidly extract proteins from their native localizations during mitosis and conditional recruitment of lipid-metabolizing enzymes for mitosis-selective editing of plasma membrane lipid content, without the need for exogenous triggers or perturbative synchronization methods.

DOI: https://doi.org/10.1101/2024.06.05.597552
Adv Sci (Weinh). 2024 Jun 17. e2308822

Tight Junction Component Occludin Binds to FIP5 to Regulate Endosome Trafficking and Mitotic Spindle Function.

Zichao Zhang, Jing Chen, Rongze Ma, Chongshen Xu, Yunzhe Lu, Jiecan Zhou, Kun Xia, Pengfei Lu.

  The genetic basis of vertebrate emergence during metazoan evolution has remained largely unknown. Understanding vertebrate-specific genes, such as the tight junction protein Occludin (Ocln), may help answer this question. Here, it is shown that mammary glands lacking Ocln exhibit retarded epithelial branching, owing to reduced cell proliferation and surface expansion. Interestingly, Ocln regulates mitotic spindle orientation and function, and its loss leads to a range of defects, including prolonged prophase and failed nuclear and/or cytoplasmic division. Mechanistically, Ocln binds to the RabGTPase-11 adaptor FIP5 and recruits recycling endosomes to the centrosome to participate in spindle assembly and function. FIP5 loss recapitulates Ocln null, leading to prolonged prophase, reduced cell proliferation, and retarded epithelial branching. These results identify a novel role in OCLN-mediated endosomal trafficking and potentially highlight its involvement in mediating membranous vesicle trafficking and function, which is evolutionarily conserved and essential.

Keywords:  RAB proteins; branching morphogenesis; centrosome; epithelial migration; spindle organization; vertebrate‐specific genes; vesicular trafficking

DOI:  https://doi.org/10.1002/advs.202308822
Curr Biol. 2024 Jun 17. pii: S0960-9822(24)00587-6. [Epub ahead of print]34(12): R565-R567

Chromosome segregation: Brushing up on centromeres.

Kerry Bloom.

Turning centromere DNA into a mechanical spring is central to the fidelity of chromosome segregation. A recent study shows how centromere DNA loops and partitioning cohesin and condensin convert centromeres and pericentromeres into bipartite bottlebrushes.

DOI: https://doi.org/10.1016/j.cub.2024.04.074
Open Biol. 2024 Jun;14(6): 240065

Greatwall-Endos-PP2A/B55Twins network regulates translation and stability of maternal transcripts in the Drosophila oocyte-to-embryo transition.

Hélène Rangone, Laura Bond, Timothy T Weil, David M Glover.

  The transition from oocyte to embryo requires translation of maternally provided transcripts that in Drosophila is activated by Pan Gu kinase to release a rapid succession of 13 mitotic cycles. Mitotic entry is promoted by several protein kinases that include Greatwall/Mastl, whose Endosulfine substrates antagonize Protein Phosphatase 2A (PP2A), facilitating mitotic Cyclin-dependent kinase 1/Cyclin B kinase activity. Here we show that hyperactive greatwallScant can not only be suppressed by mutants in its Endos substrate but also by mutants in Pan Gu kinase subunits. Conversely, mutants in me31B or trailer hitch, which encode a complex that represses hundreds of maternal mRNAs, enhance greatwallScant . Me31B and Trailer Hitch proteins, known substrates of Pan Gu kinase, copurify with Endos. This echoes findings that budding yeast Dhh1, orthologue of Me31B, associates with Igo1/2, orthologues of Endos and substrates of the Rim15, orthologue of Greatwall. endos-derived mutant embryos show reduced Me31B and elevated transcripts for the mitotic activators Cyclin B, Polo and Twine/Cdc25. Together, our findings demonstrate a previously unappreciated conservation of the Greatwall-Endosulfine pathway in regulating translational repressors and its interactions with the Pan Gu kinase pathway to regulate translation and/or stability of maternal mRNAs upon egg activation.

Keywords:  Drosophila; Endosulfine; Greatwall; Pan Gu kinase; maternal transcripts; oocyte-to-embryo transition

DOI:  https://doi.org/10.1098/rsob.240065
Biochem Biophys Res Commun. 2024 Jun 18. pii: S0006-291X(24)00811-8. [Epub ahead of print]726 150275

USP11 modulates mitotic progression and senescence by regulating the p53-p21 axis through MDM2 deubiquitination.

Won-Joo Kim, Abdul Basit, Jae-Ho Lee.

  USP11 is overexpressed in colorectal cancer (CRC) and breast cancer tissues compared to normal tissues, suggesting a role in promoting cell proliferation and inhibiting cell death. In this study, we observed that depleting USP11 inhibits cell proliferation and delays cell cycle progression. This depletion leads to increased p53 protein levels due to an extended half-life, resulting in elevated p21 mRNA levels in a p53-dependent manner. The rise in p53 protein upon USP11 depletion is linked to a reduced half-life of MDM2, a known E3 ligase for p53, via enhanced polyubiquitination of MDM2. These findings indicate that USP11 might act as a deubiquitinase for MDM2, regulating the MDM2-p53-p21 axis. Additionally, USP11 depletion promotes the induction of senescent cells in a manner dependent on its deubiquitinase activity. Our findings provide insights into the physiological significance of high USP11 expression in primary tumors and its reduction in senescent cells, highlighting its potential as a therapeutic target.

Keywords:  Cell cycle arrest; Protein stability; Senescence; USP11; p21; p53

DOI:  https://doi.org/10.1016/j.bbrc.2024.150275
Genetics. 2024 Jun 17. pii: iyae102. [Epub ahead of print]

The chromatin-associated 53BP1 ortholog, HSR-9, regulates recombinational repair and X chromosome segregation in the Caenorhabditis elegans germ line.

Qianyan Li, Sara Hariri, Aashna Calidas, Arshdeep Kaur, Erica Huey, JoAnne Engebrecht.

  53BP1 plays a crucial role in regulating DNA damage repair pathway choice and checkpoint signaling in somatic cells; however, its role in meiosis has remained enigmatic. In this study, we demonstrate that the Caenorhabditis elegans ortholog of 53BP1, HSR-9, associates with chromatin in both proliferating and meiotic germ cells. Notably, HSR-9 is enriched on the X chromosome pair in pachytene oogenic germ cells. HSR-9 is also present at kinetochores during both mitotic and meiotic divisions but does not appear to be essential for monitoring microtubule-kinetochore attachments or tension. Using cytological markers of different steps in recombinational repair, we found that HSR-9 influences the processing of a subset of meiotic double strand breaks into COSA-1-marked crossovers. Additionally, HSR-9 plays a role in meiotic X chromosome segregation under conditions where X chromosomes fail to pair, synapse, and recombine. Together, these results highlight that chromatin-associated HSR-9 has both conserved and unique functions in the regulation of meiotic chromosome behavior.

Keywords:   C. elegans ; 53BP1; HSR-9; checkpoint; meiosis; recombination; sex chromosomes

DOI:  https://doi.org/10.1093/genetics/iyae102
Mol Cell Biol. 2024 Jun 12. 1-13

Phosphorylation of Orc6 During Mitosis Regulates DNA Replication and Ribosome Biogenesis.

Fredy Kurniawan, Arindam Chakraborty, Humayra Z Oishi, Minxue Liu, Mariam K Arif, David Chen, Rishabh Prasanth, Yo-Chuen Lin, Godwin Olalaye, Kannanganattu V Prasanth, Supriya G Prasanth.

  The human Origin Recognition Complex (ORC) is required not only for the initiation of DNA replication, but is also implicated in diverse cellular functions, including chromatin organization, centrosome biology, and cytokinesis. The smallest subunit of ORC, Orc6, is poorly conserved amongst eukaryotes. Recent studies from our laboratory have suggested that human Orc6 is not required for replication licensing, but is needed for S-phase progression. Further, ATR-dependent phosphorylation of Orc6 at T229 is implicated in DNA damage response during S-phase. In this study, we demonstrate that the CDK-dependent phosphorylation of Orc6 at T195 occurs during mitosis. While the phosphorylation at T195 does not seem to be required to exit mitosis, cells expressing the phosphomimetic T195E mutant of Orc6 impede S-phase progression. Moreover, the phosphorylated form of Orc6 associates with ORC more robustly, and Orc6 shows enhanced association with the ORC outside of G1, supporting the view that Orc6 may prevent the role of Orc1-5 in licensing outside of G1. Finally, Orc6 and the phosphorylated Orc6 localize to the nucleolar organizing centers and regulate ribosome biogenesis. Our results suggest that phosphorylated Orc6 at T195 prevents replication.

Keywords:  Mitosis; Orc6; nucleolus; phosphorylation; replication

DOI:  https://doi.org/10.1080/10985549.2024.2356880