title: Arp2 links autophagic machinery with the actin cytoskeleton.
abstract: Macroautophagy involves lysosomal/vacuolar elimination of long-lived proteins and entire organelles from the cytosol. The process begins with formation of a double-membrane vesicle that sequesters bulk cytoplasm, or a specific cargo destined for lysosomal/vacuolar delivery. The completed vesicle fuses with the lysosome/vacuole limiting membrane, releasing its content into the organelle lumen for subsequent degradation and recycling of the resulting macromolecules. A majority of the autophagy-related (Atg) proteins are required at the step of vesicle formation. The integral membrane protein Atg9 cycles between certain intracellular compartments and the vesicle nucleation site, presumably to supply membranes necessary for macroautophagic vesicle formation. In this study we have tracked the movement of Atg9 over time in living cells by using real-time fluorescence microscopy. Our results reveal that an actin-related protein, Arp2, briefly colocalizes with Atg9 and directly regulates the dynamics of Atg9 movement. We propose that proteins of the Arp2/3 complex regulate Atg9 transport for specific types of autophagy.
authors.affiliation: Life Sciences Institute and Departments of Molecular, Cellular, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Iryna
authors.initials: I
authors.lastname: Monastyrska
authors.forename: Congcong
authors.initials: C
authors.lastname: He
authors.forename: Jiefei
authors.initials: J
authors.lastname: Geng
authors.forename: Adam D
authors.initials: AD
authors.lastname: Hoppe
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Li
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Klionsky
mesh_terms: D051377:Actin-Related Protein 2 / Q000378:metabolism*; D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D001343:Autophagy; D000071183:Autophagy-Related Proteins; D003599:Cytoskeleton / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000378:metabolism
chemical_list: C477632:ARP2 protein, S cerevisiae; C434065:ATG9 protein, S cerevisiae; D051377:Actin-Related Protein 2; D051376:Actin-Related Protein 2-3 Complex; D000199:Actins; C502923:Atg11 protein, S cerevisiae; D000071183:Autophagy-Related Proteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins