title: Tiered assembly of the yeast Far3-7-8-9-10-11 complex at the endoplasmic reticulum.
abstract: Target of rapamycin signaling is a conserved, essential pathway integrating nutritional cues with cell growth and proliferation. The target of rapamycin kinase exists in two distinct complexes, TORC1 and TORC2. It has been reported that protein phosphatase 2A (PP2A) and the Far3-7-8-9-10-11 complex (Far complex) negatively regulate TORC2 signaling in yeast. The Far complex, originally identified as factors required for pheromone-induced cell cycle arrest, and PP2A form the yeast counterpart of the STRIPAK complex, which was first isolated in mammals. The cellular localization of the Far complex has yet to be fully characterized. Here, we show that the Far complex localizes to the endoplasmic reticulum (ER) by analyzing functional GFP-tagged Far proteins in vivo. We found that Far9 and Far10, two homologous proteins each with a tail-anchor domain, localize to the ER in mutant cells lacking the other Far complex components. Far3, Far7, and Far8 form a subcomplex, which is recruited to the ER by Far9/10. The Far3-7-8- complex in turn recruits Far11 to the ER. Finally, we show that the tail-anchor domain of Far9 is required for its optimal function in TORC2 signaling. Our study reveals tiered assembly of the yeast Far complex at the ER and a function for Far complex's ER localization in TORC2 signaling.
authors.affiliation: Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana 70148.
authors.forename: Tammy
authors.initials: T
authors.lastname: Pracheil
authors.affiliation: Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana 70148. Electronic address: zliu5@uno.edu.
authors.forename: Zhengchang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism*; D000076225:Mechanistic Target of Rapamycin Complex 2; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; C472672:FAR11 protein, S cerevisiae; C096755:FAR3 protein, S cerevisiae; C472670:FAR7 protein, S cerevisiae; C472671:FAR9 protein, S cerevisiae; D046912:Multiprotein Complexes; D029701:Saccharomyces cerevisiae Proteins; C561842:TORC1 protein complex, S cerevisiae; D014157:Transcription Factors; D000076225:Mechanistic Target of Rapamycin Complex 2; D058570:TOR Serine-Threonine Kinases; D054648:Protein Phosphatase 2
keywords: Endoplasmic Reticulum (ER); Far3-7-8-9-10-11; PP2A; Protein Complexes; STRIPAK Complex; Saccharomyces cerevisiae; TOR Complex (TORC); TORC2 Signaling; Tail-anchored Proteins; Yeast