Saccharomyces cerevisiae SFP1: at the crossroads of central metabolism and ribosome biogenesis

Abstract

Saccharomyces cerevisiae SFP1 is required for nutrient-dependent regulation of ribosome biogenesis and cell size. A mutant deleted for SFP1 shows specific traits, including a slow growth phenotype, especially when growing on glucose. We recently analysed the physiology of an sfp1D mutant and its isogenic reference strain in chemostat cultures. This approach was successful in revealing the effects of nutrients on the activity of Sfp1 independent of growth rate-related feedback. In the present work we exposed carbon-limited cultures of an sfp1D mutant and its reference strain to sudden glucose excess. This allowed us to study the effect of SFP1 deletion on cell physiology when the cells are forced to exploit their maximum growth potential; this is similar to what happens in shake-flask cultures but with no bias due to growth rate differences. We show that nutrients differentiallly affect the role of Sfp1 in cell-size modulation and in transcriptional control. Furthermore, we report that while Sfp1 is necessary for the efficient glucose-dependent regulation of ribosome biogenesis genes, it is not required for the proper induction of ribosomal protein genes in response to glucose excess. Finally, our data suggest a role for Sfp1 in the regulation of glycolysis, further underlining its involvement in the network that links ribosome biogenesis and cell metabolism.

Stb3 Plays a Role in the Glucose-Induced Transition from Quiescence to Growth inSaccharomyces cerevisiae

“…Sfp1 is thought to lie even farther downstream of Tor, interacting with DNA binding proteins that regulate RP expression and playing a more poorly understood role in controlling non-RP growth genes ( Jorgensen et al 2004;Cipollina et al 2008;Lempiainen et al 2009). Sfp1 is therefore a regulator of the growth response to glucose repletion.…”

A Rab escort protein integrates the secretion system with TOR signaling and ribosome biogenesis

“…The MRS6-R alleles also a caused delay in the repression of glycolysis genes (Fig. 6A); this may also be a downstream consequence of Ribi repression (Jorgensen et al 2002), or may reflect a more direct role for Sfp1, Mrs6, and/or TORC1 in glycolytic gene regulation (Hardwick et al 1999;Cipollina et al 2008). The MRS6-R alleles had only a minor effect on activation of the NCR regulon by rapamycin (Fig.…”

Distinguishing Direct versus Indirect Transcription Factor-DNA Interactions

“…The Sfp1 motif is ranked 44 th , with much lower enrichment (AUC = 0.740) and an insignificant P-value (P = 0.597). Sfp1 is required for nutrient-dependent regulation of ribosome biogenesis (Fingerman et al 2003) and cell size (Cipollina et al 2008). Additionally, Sfp1 has been shown to regulate ribosomal protein (RP) gene transcription (Fingerman et al 2003).…”