title: Endocytic recycling in yeast is regulated by putative phospholipid translocases and the Ypt31p/32p-Rcy1p pathway.
abstract: Phospholipid translocases (PLTs) have been implicated in the generation of phospholipid asymmetry in membrane bilayers. In budding yeast, putative PLTs are encoded by the DRS2 gene family of type 4 P-type ATPases. The homologous proteins Cdc50p, Lem3p, and Crf1p are potential noncatalytic subunits of Drs2p, Dnf1p and Dnf2p, and Dnf3p, respectively; these putative heteromeric PLTs share an essential function for cell growth. We constructed temperature-sensitive mutants of CDC50 in the lem3Delta crf1Delta background (cdc50-ts mutants). Screening for multicopy suppressors of cdc50-ts identified YPT31/32, two genes that encode Rab family small GTPases that are involved in both the exocytic and endocytic recycling pathways. The cdc50-ts mutants did not exhibit major defects in the exocytic pathways, but they did exhibit those in endocytic recycling; large membranous structures containing the vesicle-soluble N-ethylmaleimide-sensitive factor attachment protein receptor Snc1p intracellularly accumulated in these mutants. Genetic results suggested that the YPT31/32 effector RCY1 and CDC50 function in the same signaling pathway, and simultaneous overexpression of CDC50, DRS2, and GFP-SNC1 restored growth as well as the plasma membrane localization of GFP-Snc1p in the rcy1Delta mutant. In addition, Rcy1p coimmunoprecipitated with Cdc50p-Drs2p. We propose that the Ypt31p/32p-Rcy1p pathway regulates putative phospholipid translocases to promote formation of vesicles destined for the trans-Golgi network from early endosomes.
authors.affiliation: Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-0815, Japan.
authors.forename: Nobumichi
authors.initials: N
authors.lastname: Furuta
authors.forename: Konomi
authors.initials: K
authors.lastname: Fujimura-Kamada
authors.forename: Koji
authors.initials: K
authors.lastname: Saito
authors.forename: Takaharu
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Kazuma
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004705:Endocytosis; D011992:Endosomes / Q000648:ultrastructure; D044783:F-Box Proteins; D005656:Fungal Proteins / Q000378:metabolism; D015870:Gene Expression; D016153:Genes, Suppressor; D008565:Membrane Proteins / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D049294:Phospholipid Transfer Proteins / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport; D050683:R-SNARE Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000302:isolation & purification / Q000378:metabolism*; D022142:Secretory Vesicles / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism
chemical_list: C427246:CDC50 protein, S cerevisiae; C104014:DRS2 protein, S cerevisiae; D044783:F-Box Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; D046912:Multiprotein Complexes; D049294:Phospholipid Transfer Proteins; D050683:R-SNARE Proteins; C407703:RCY1 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; C083241:SNC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C503584:Tlg1 protein, S cerevisiae; D033921:Vesicular Transport Proteins; C087905:YPT31 protein, S cerevisiae; C121633:YPT32 protein, S cerevisiae; D020691:rab GTP-Binding Proteins; D000252:Calcium-Transporting ATPases