title: Yeast RSC function is required for organization of the cellular cytoskeleton via an alternative PKC1 pathway.
abstract: RSC is a 15-protein ATP-dependent chromatin-remodeling complex related to Snf-Swi, the prototypical ATP-dependent nucleosome remodeler in budding yeast. Despite insight into the mechanism by which purified RSC remodels nucleosomes, little is known about the chromosomal targets or cellular pathways in which RSC acts. To better understand the cellular function of RSC, a screen was undertaken for gene dosage suppressors of sth1-3ts, a temperature-sensitive mutation in STH1, which encodes the essential ATPase subunit. Slg1p and Mid2p, two type I transmembrane stress sensors of cell wall integrity that function upstream of protein kinase C (Pkc1p), were identified as multicopy suppressors of sth1-3ts cells. Although the sth1-3ts mutant exhibits defects characteristic of PKC1 pathway mutants (caffeine and staurosporine sensitivities and an osmoremedial phenotype), only upstream components and not downstream effectors of the PKC1-MAP kinase pathway can suppress defects conferred by sth1-3ts, suggesting that RSC functions in an alternative PKC1-dependent pathway. Moreover, sth1-3ts cells display defects in actin cytoskeletal rearrangements and are hypersensitive to the microtubule depolymerizing drug, TBZ; both of these defects can be corrected by the high-copy suppressors. Together, these data reveal an important functional connection between the RSC remodeler and PKC1-dependent signaling in regulating the cellular architecture.
authors.affiliation: Department of Microbiology and Immunology and Morse Institute for Molecular Genetics, State University of New York, Brooklyn, New York 11203, USA.
authors.forename: Bob
authors.initials: B
authors.lastname: Chai
authors.forename: Jing-mei
authors.initials: JM
authors.lastname: Hsu
authors.forename: Jian
authors.initials: J
authors.lastname: Du
authors.forename: Brehon C
authors.initials: BC
authors.lastname: Laurent
mesh_terms: D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins; D003599:Cytoskeleton / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020536:Enzyme Activators / Q000378:metabolism; D006358:Hot Temperature; D047908:Intracellular Signaling Peptides and Proteins; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013827:Thiabendazole / Q000037:antagonists & inhibitors / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D020536:Enzyme Activators; D047908:Intracellular Signaling Peptides and Proteins; C091625:MID2 protein, S cerevisiae; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; C103337:RSC complex, S cerevisiae; C119383:SLG1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011493:Protein Kinase C; C077392:STH1 protein, S cerevisiae; D013827:Thiabendazole