Recruitment of Atg9 to the preautophagosomal structure by Atg11 is essential for selective autophagy in budding yeast.
Autophagy is a conserved degradative pathway that is induced in response to various stress and developmental conditions in eukaryotic cells. It allows the elimination of cytosolic proteins and organelles in the lysosome/vacuole. In the yeast Saccharomyces cerevisiae, the integral membrane protein Atg9 (autophagy-related protein 9) cycles between mitochondria and the preautophagosomal structure (PAS), the nucleating site for formation of the sequestering vesicle, suggesting a role in supplying membrane for vesicle formation and/or expansion during autophagy. To better understand the mechanisms involved in Atg9 cycling, we performed a yeast two-hybrid-based screen and identified a peripheral membrane protein, Atg11, that interacts with Atg9. We show that Atg11 governs Atg9 cycling through the PAS during specific autophagy. We also demonstrate that the integrity of the actin cytoskeleton is essential for correct targeting of Atg11 to the PAS. We propose that a pool of Atg11 mediates the anterograde transport of Atg9 to the PAS that is dependent on the actin cytoskeleton during yeast vegetative growth.
He
Congcong
C
Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
Song
Hui
H
Yorimitsu
Tomohiro
T
Monastyrska
Iryna
I
Yen
Wei-Lien
WL
Legakis
Julie E
JE
Klionsky
Daniel J
DJ
D000199:Actins / Q000378:metabolism; D001343:Autophagy; D000071183:Autophagy-Related Proteins; D003593:Cytoplasm / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D010588:Phagosomes / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*
C434065:ATG9 protein, S cerevisiae; D000199:Actins; C502923:Atg11 protein, S cerevisiae; D000071183:Autophagy-Related Proteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins