title: MAF1: a new target of mTORC1.
abstract: Yeast and mammalian MAF1 are both regulated by the TOR (target of rapamycin) pathway. However, the exact mechanisms of regulation diverge at TOR, with yeast Maf1 phosphorylated mainly by the TORC1 (TOR complex 1) substrate Sch9 kinase and mammalian MAF1 by mTORC1 (mammalian target of rapamycin complex 1) itself. Sch9 phosphorylation of yeast Maf1 regulates Maf1 localization, but it is less clear whether phosphorylation of human MAF1 regulates its localization. Replacement of phosphosites with alanine decreases Pol III (RNA polymerase III) transcription, but the effect is much more pronounced for human MAF1 than for the yeast protein. In both cases, Pol III repression can be further increased by rapamycin treatment or, in mammalian cells, serum starvation, suggesting that the TOR pathway controls another aspect of Pol III transcription that is closely linked to MAF1, as it depends on the presence of MAF1.
authors.affiliation: Center for Integrative Genomics (CIG), Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland. Annemieke.Michels@unil.ch
authors.forename: Annemieke A
authors.initials: AA
authors.lastname: Michels
mesh_terms: D000818:Animals; D020134:Catalytic Domain; D006801:Humans; D000076222:Mechanistic Target of Rapamycin Complex 1; D008954:Models, Biological; D046912:Multiprotein Complexes; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism / Q000502:physiology; D021381:Protein Transport; D011506:Proteins / Q000378:metabolism / Q000502:physiology*; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology; D058570:TOR Serine-Threonine Kinases; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
chemical_list: C520535:MAF1 protein, human; D046912:Multiprotein Complexes; D011506:Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D000076222:Mechanistic Target of Rapamycin Complex 1; D017346:Protein Serine-Threonine Kinases; C530964:SCH9 protein, S cerevisiae; D058570:TOR Serine-Threonine Kinases