RSC1 and RSC2 Are Required for Expression of Mid-Late Sporulation-Specific Genes in Saccharomyces cerevisiae

Abstract

Rsc1 and Rsc2 are alternative bromodomain-containing subunits of the ATP-dependent RSC chromatin remodeling complex in Saccharomyces cerevisiae. Smk1 is a sporulation-specific mitogen-activated protein kinase homolog that is required for the postmeiotic events of spore formation. In this study we show that RSC1 and RSC2 are haploinsufficient for spore formation in a smk1 hypomorph. Moreover, diploids lacking Rsc1 or Rsc2 show a subset of smk1-like phenotypes. High-copy-number RSC1 plasmids do not suppress rsc2-⌬/rsc2-⌬ sporulation defects, and high-copy-number RSC2 plasmids do not suppress rsc1-⌬/rsc1-⌬ sporulation defects. Mid-late sporulation-specific genes, which are normally expressed while key steps in spore assembly occur and which include genes that are required for spore wall formation, are not expressed in cells lacking Rsc1 or Rsc2. We speculate that the combined action of Rsc1 and Rsc2 at mid-late promoters is specifically required for the proper expression of this uniquely timed set of genes. Our data suggest that Smk1 and Rsc1/2 define parallel pathways that converge to provide signaling information and the expression of gene products, respectively, that are required for spore morphogenesis.

Genome-wide screen for inositol auxotrophy in Saccharomyces cerevisiae implicates lipid metabolism in stress response signaling

“…We report Ino − phenotypes in rsc1Δ and rsc2Δ mutants, affecting the Remodel the Structure of Chromatin (RSC) complex (Chai et al 2002; Bungard et al 2004), which is related to SWI/SNF complex (Tables 3, S1) and ies1Δ , ies2Δ , ies4Δ , ies5Δ , and nhp10Δ mutants, which affect INO80 complex (Tables 3, S1). …”

Ascospore Formation in the YeastSaccharomyces cerevisiae

“…Thus, there must be an activating kinase for Smk1p. Hypomorphic mutations of the essential CAK1 or MPS1 genes produce spore wall defects similar to those seen in smk1 mutants, although unlike Smk1p, both of these kinases have distinct functions earlier in sporulation (19,148,150,161,177). In vegetative cells, CAK1 is required for phosphorylation of Cdc28p and other cyclin-dependent kinases on a threonine in an analogous position to the activating phosphorylation sites in Smk1p (37,69,117,184).…”

The RSC Chromatin Remodeling Complex Bears an Essential Fungal-Specific Protein Module With Broad Functional Roles

“…In RSC, the catalytic ATPase is essential for viability (Du et al 1998) and is also sufficient for remodeling in vitro (Saha et al 2002). Mutations in other RSC members also confer lethality or conditional phenotypes suggesting important in vivo functions for these attendant subunits (Cao et al 1997;Treich and Carlson 1997;Cairns et al 1998Cairns et al , 1999Treich et al 1998;Damelin et al 2002;Saha et al 2002;Bungard et al 2004;Taneda and Kikuchi 2004). Mutations in certain RSC subunits (Sth1, Htl1, Rsc3, and Rsc4) confer cell wall defects (osmotically remedial temperature sensitivity) and link RSC to the cell wall integrity pathway likely through proper transcriptional regulation of cell wall components/regulators (Angus-Hill et al 2001;Chai et al 2002;Romeo et al 2002;Kasten et al 2004).…”