Phosphorylation of Atg31 is required for autophagy

• Published in: Protein & cell Vol. 6; no. 4; pp. 288 - 296
• Main Authors: Feng, Wenzhi, Wu, Tong, Dan, Xiaoyu, Chen, Yuling, Li, Lin, Chen, She, Miao, Di, Deng, Haiteng, Gong, Xinqi, Yu, Li
• Format: Journal Article
• Language: English
• Published: Heidelberg Higher Education Press 01.04.2015; Springer Nature B.V
• Subjects: Alanine - chemistry; Alanine - metabolism; Amino Acid Motifs; Aspartic Acid - chemistry; Aspartic Acid - metabolism; Atg31; autophagosome; autophagy; Autophagy - genetics; Autophagy-Related Proteins; Biochemistry; Biomedical and Life Sciences; Carrier Proteins - chemistry; Carrier Proteins - metabolism; Cell Biology; Developmental Biology; Gene Expression Regulation, Fungal; Human Genetics; Life Sciences; Membrane Proteins - chemistry; Membrane Proteins - metabolism; Models, Molecular; Molecular Sequence Data; Nitrogen - deficiency; PAS; Phagosomes - chemistry; Phagosomes - drug effects; Phagosomes - metabolism; Phosphorylation; pre-autophagosomal structure (PAS); Protein Science; Protein Transport; Research Article; Saccharomyces cerevisiae - drug effects; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Serine - chemistry; Serine - metabolism; Signal Transduction; Sirolimus - pharmacology; Stem Cells; 功能障碍; 磷酸化位点; 磷酸化氨基酸; 磷酸化蛋白; 缺失突变体; 自噬; 质谱分析; Atg31; pre-autophagosomal structure (PAS); autophagy; phosphorylation; autophagosome
• ISSN: 1674-800X; 1674-8018; 1674-8018
• DOI: 10.1007/s13238-015-0138-4

Autophagy is an evolutionarily conserved cellular pro- cess which degrades intracellular contents. The Atg17- Atg31-Atg29 complex plays a key role in autophagy in- duction by various stimuli. In yeast, autophagy occurs with autophagosome formation at a special site near the vacuole named the pre-autophagosomal structure （PAS）. The Atg17-Atg31-Atg29 complex forms a scaffold for PAS organization, and recruits other autophagy-re- lated （Atg） proteins to the PAS. Here, we show that Atg31 is a phosphorylated protein. The phosphorylation sites on Atg31 were identified by mass spectrometry. Analy- sis of mutants in which the phosphorylated amino acids were replaced by alanine, either individually or in var- ious combinations, identified S174 as the functional phosphorylation site. An S174A mutant showed a simi- lar degree of autophagy impairment as an Atg31 deletion mutant. S174 phosphorylation is required for autophagy induced by various autophagy stimuli such as nitrogen starvation and rapamycin treatment. Mass spectrometry analysis showed that S174 is phosphorylated constitu- tively, and expression of a phosphorylation-mimic mu- tant （S174D） in the Atg31 deletion strain restores autophagy. In the S174A mutant, Atg9-positive vesicles accumulate at the PAS. Thus, S174 phosphorylation is required for formation of autophagosomes, possibly by facilitating the recycling of Atg9 from the PAS. Our data demonstrate the role of phosphorylation of Atg31 in autophagy.