bims-nocaut 2025-02-09 papers

Issue of 2025–02–09
three papers selected by
Quentin Frenger, University of Strasbourg

J Mol Biol. 2025 Feb 03. pii: S0022-2836(25)00047-6. [Epub ahead of print] 168981

Multifaceted roles of the ATG8 protein family in plant autophagy: from autophagosome biogenesis to cargo recognition.

In plant cells, autophagy is an essential quality control process by forming a double-membrane structure named the autophagosome, which envelopes and transports the cargoes to the vacuole for degradation/recycling. Autophagy-related (ATG) 8, a key regulator in autophagy, exerts multifunctional roles during autophagy. ATG8 anchors on the phagophore membrane through the ATG8 conjugation system and participates in different steps during autophagosome formation. Accumulating evidence has demonstrated that ATG8 cooperates with other ATG or non-ATG proteins in autophagosome biogenesis. Meanwhile, ATG8 plays an important role in cargo recognition, which is mainly attributed by the specific interactions between ATG8 and the selective autophagy receptors (SARs) or cargos for selective autophagy. Emerging roles of ATG8 in non-canonical autophagy have been recently reported in plants for different stress adaptation. Here, we review the diverse functions of ATG8 in plants, focusing on autophagosome biogenesis and cargo recognition in canonical and non-canonical autophagy.

Keywords: ATG8 protein family; ATG8ylation; autophagosome formation; non-canonical autophagy; plants; selective autophagy

DOI: https://doi.org/10.1016/j.jmb.2025.168981

Nat Commun. 2025 Feb 04. 16(1): 1343

The autophagy component LC3 regulates lymphocyte adhesion via LFA1 transport in response to outside-in signaling.

Naoyuki Kondo, Yuko Mimori-Kiyosue, Keizo Tokuhiro, Giuseppe Pezzotti, Tatsuo Kinashi.

The leukocyte integrin LFA1 is indispensable for immune responses, orchestrating lymphocyte trafficking and adhesion. While LFA1 activation induces LFA1 clustering at the cell contact surface via outside-in signaling, the regulatory mechanisms remain unclear. Here, we uncovered a previously hidden function of the autophagosome component LC3 beyond its role in autophagy by bridging two seemingly unrelated pathways: LFA1 transport and autophagosome transport. LFA1 clusters co-trafficked with LC3, facilitating LFA1 accumulation at the contact surface. LC3b knockout decreased lymphocyte adhesiveness. LFA1 activation did not induce autophagy, whereas it increased mTOR and AMPK activity. LFA1-dependent AMPK activation enhances LFA1 and LC3 clustering and adhesion. Inhibiting Mst1 kinase-mediated LC3 phosphorylation promoted LC3-mediated LFA1 recruitment to the contact surface through direct interaction with RAPL, uncovering an unprecedented integrin recruitment route. These findings uncover a function of LC3 and expand our understanding of lymphocyte regulation via LFA1.

DOI: https://doi.org/10.1038/s41467-025-56631-1

Nat Plants. 2025 Feb 07.

ATG8ylation of vacuolar membrane protects plants against cell wall damage.

Vacuoles are essential for cellular metabolism and growth and the maintenance of internal turgor pressure. They sequester lytic enzymes, ions and secondary metabolites that, if leaked into the cytosol, could lead to cell death. Despite their pivotal roles, quality control pathways that safeguard vacuolar integrity have remained elusive in plants. Here we describe a conserved vacuolar quality control pathway that is activated upon cell wall damage in a turgor-pressure-dependent manner. Cell wall perturbations induce a distinct modification-ATG8ylation-on the vacuolar membrane (tonoplast) that is regulated by the V-ATPase and ATG8 conjugation machinery. Genetic disruption of tonoplast ATG8ylation impairs vacuolar integrity, leading to cell death. Together, our findings reveal a homeostatic pathway that preserves vacuolar integrity upon cell wall damage.

DOI: https://doi.org/10.1038/s41477-025-01907-z