title: Vps51 is part of the yeast Vps fifty-three tethering complex essential for retrograde traffic from the early endosome and Cvt vesicle completion.
abstract: Autophagy, pexophagy, and the Cvt pathway are processes that deliver hydrolytic enzymes and substrates to the yeast vacuole/lysosome via double-membrane cytosolic vesicles. Whereas these pathways operate under different nutritional conditions, they all employ common machinery with only a few specific factors assisting in the choice of the delivery program and the membrane source for the sequestering vesicle. We found that the YKR020w gene product is essential for Cvt vesicle formation but not for pexophagy or induction of autophagy. Autophagosomes in the ykr020wdelta mutant, however, have a reduced size. We demonstrate that Ykr020 is a subunit of the Vps fifty-three tethering complex, composed of Vps52, Vps53, and Vps54, which is required for retrograde traffic from the early endosome back to the late Golgi, and for this reason we named it Vps51. This complex participates in a fusion event together with Tlg1 and Tlg2, two SNAREs also shown to be necessary for Cvt vesicle assembly. In particular, those factors are essential to correctly target the prApe1-Cvt19-Cvt9 complex to the preautophagosomal structure, the site of Cvt vesicle formation.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1048, USA.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Reggiori
authors.forename: Chao-Wen
authors.initials: CW
authors.lastname: Wang
authors.forename: Per E
authors.initials: PE
authors.lastname: Stromhaug
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shintani
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Klionsky
mesh_terms: D001692:Biological Transport; D011992:Endosomes / Q000378:metabolism*; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism*; D033921:Vesicular Transport Proteins
chemical_list: D008565:Membrane Proteins; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; C117606:VPS54 protein, S cerevisiae; D033921:Vesicular Transport Proteins