biostudies-literatureYe HResearch Grants Council, University Grants CommitteeNational Natural Science Foundation of Chinae2205314119https://www.ebi.ac.uk/biostudies/studies/S-EPMC9618059biostudies-literatureUnknown119(43)Autophagy is an intracellular degradation system for cytoplasmic constituents which is mediated by the formation of a double-membrane organelle termed the autophagosome and its subsequent fusion with the lysosome/vacuole. The formation of the autophagosome requires membrane from the endoplasmic reticulum (ER) and is tightly regulated by a series of autophagy-related (ATG) proteins and lipids. However, how the ER contacts autophagosomes and regulates autophagy remain elusive in plants. In this study, we identified and demonstrated the roles of <i>Arabidopsis</i> oxysterol-binding protein-related protein 2A (ORP2A) in mediating ER-autophagosomal membrane contacts and autophagosome biogenesis. We showed that ORP2A localizes to both ER-plasma membrane contact sites (EPCSs) and autophagosomes, Proceedings of the National Academy of Sciences of the United States of America<i>Arabidopsis</i> ORP2A mediates ER-autophagosomal membrane contact sites and regulates PI3P in plant autophagy.PMC961805991854201C4002-20WC4033-19EC2009-19GCUHK14101219C4041-18EC4002-21EFC4002-17GAoE/M-05/12R4005-18CUHK14100818Huang SJiang LLiang ZYu QGao JLin YYe Hfalse<i>Arabidopsis</i> ORP2A mediates ER-autophagosomal membrane contact sites and regulates PI3P in plant autophagy.Autophagy is an intracellular degradation system for cytoplasmic constituents which is mediated by the formation of a double-membrane organelle termed the autophagosome and its subsequent fusion with the lysosome/vacuole. The formation of the autophagosome requires membrane from the endoplasmic reticulum (ER) and is tightly regulated by a series of autophagy-related (ATG) proteins and lipids. However, how the ER contacts autophagosomes and regulates autophagy remain elusive in plants. In this study, we identified and demonstrated the roles of <i>Arabidopsis</i> oxysterol-binding protein-related protein 2A (ORP2A) in mediating ER-autophagosomal membrane contacts and autophagosome biogenesis. We showed that ORP2A localizes to both ER-plasma membrane contact sites (EPCSs) and autophagosomes, 2022-01-01T00:00:00Z2022 Oct2025-04-04T20:46:03.357Z2025-04-04T20:46:03.357ZS-EPMC96180593625202810.1073/pnas.2205314119