Yeast Atg8 and its homologs are involved in autophagosome biogenesis in all eukaryotes. These are the most widely used markers for autophagy thanks to the association of their lipidated forms with autophagic membranes. The Atg8 protein family expanded in animals and plants, with most species having two Atg8 homologs. In this Brief Report, we use clear-cut genetic analysis in to show that lipidated Atg8a is required for autophagy, while its non-lipidated form is essential for developmentally programmed larval midgut elimination and viability. In contrast, expression of Atg8b is restricted to the male germline and its loss causes male sterility without affecting autophagy. We find that high expression of non-lipidated Atg8b in the male germline is required for fertility. Consistent with these non-canonical functions of Atg8 proteins, loss of genes required for Atg8 lipidation lead to autophagy defects but do not cause lethality or male sterility.
Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, MOE Key Laboratory & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China. Electronic address:
In eukaryotic cells, autophagosomes are double-membrane vesicles that are highly mobile and traffic along cytoskeletal tracks. While core autophagy-related proteins (ATGs) and other regulators involved in autophagosome biogenesis in plants have been extensively studied, the specific components regulating plant autophagosome motility remain elusive. In this study, using TurboID-based proximity labelling, we identify the retromer subcomplex comprising sorting nexin 1 (SNX1), SNX2a, and SNX2b as interacting partners of ATG8.
State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China.
Autophagosomes are formed by the enlargement and sealing of phagophores. This is accompanied by the recruitment and release of autophagy-related (Atg) proteins that function therein. Presently, the relationship among factors that act after the initial emergence of the phagophore is unclear.
Macroautophagy/autophagy, an evolutionarily conserved cellular degradation pathway, involves phagophores that sequester cytoplasmic constituents and mature into autophagosomes for subsequent lysosomal delivery. The gene family, comprising the and subfamilies in mammals, encodes ubiquitin-like proteins that are conjugated to phagophore membranes during autophagosome biogenesis. A central question in the field is how Atg8-family proteins are precisely involved in autophagosome formation, which remains controversial and challenging, at least in part due to the short lifespan of phagophores.
Jiangsu Key Laboratory for Pathogens and Ecosystems, School of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China. Electronic address:
Glutaredoxins (Grxs) are small, heat-stable proteins that serve as multi-functional glutathione （GSH）-dependent thiol transferases. Recent studies have elucidated their role in regulating cellular iron and copper homeostases. In Schizosaccharomyces pombe, five Grxs (Grx1-5) have been identified.
LC3 (microtubule-associated protein 1 light chain 3, called Atg8 in yeast and ) is one of the most well-studied autophagy-related proteins. LC3 controls the selectivity of autophagic degradation by interacting with LIR (LC3-interacting region) motifs also known as AIM (Atg8-interacting motifs) on selective autophagy receptors that carry cargo for degradation. Although the function of Atg8 family proteins is primarily cytoplasmic, they are also enriched in the nucleus.
