GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:15466158

From GONUTS
Jump to: navigation, search
Citation

Jorgensen, P, Rupes, I, Sharom, JR, Schneper, L, Broach, JR and Tyers, M (2004) A dynamic transcriptional network communicates growth potential to ribosome synthesis and critical cell size. Genes Dev. 18:2491-505

Abstract

Cell-size homeostasis entails a fundamental balance between growth and division. The budding yeast Saccharomyces cerevisiae establishes this balance by enforcing growth to a critical cell size prior to cell cycle commitment (Start) in late G1 phase. Nutrients modulate the critical size threshold, such that cells are large in rich medium and small in poor medium. Here, we show that two potent negative regulators of Start, Sfp1 and Sch9, are activators of the ribosomal protein (RP) and ribosome biogenesis (Ribi) regulons, the transcriptional programs that dictate ribosome synthesis rate in accord with environmental and intracellular conditions. Sfp1 and Sch9 are required for carbon-source modulation of cell size and are regulated at the level of nuclear localization and abundance, respectively. Sfp1 nuclear concentration responds rapidly to nutrient and stress conditions and is regulated by the Ras/PKA and TOR signaling pathways. In turn, Sfp1 influences the nuclear localization of Fhl1 and Ifh1, which bind to RP gene promoters. Starvation or the absence of Sfp1 causes Fhl1 and Ifh1 to localize to nucleolar regions, concomitant with reduced RP gene transcription. These findings suggest that nutrient signals set the critical cell-size threshold via Sfp1 and Sch9-mediated control of ribosome biosynthetic rates.

Links

PubMed PMC529537 Online version:10.1101/gad.1228804

Keywords

AMP-Activated Protein Kinases; Blotting, Northern; Cell Cycle/physiology; Cell Growth Processes/physiology; DNA-Binding Proteins/metabolism; Fungal Proteins/metabolism; Fungal Proteins/physiology; Gene Expression Profiling; Gene Expression Regulation, Fungal; Green Fluorescent Proteins; Immunoprecipitation; Microscopy; Protein Kinases/metabolism; Protein Kinases/physiology; Ribosomal Proteins/metabolism; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins/metabolism; Signal Transduction/physiology; Trans-Activators/metabolism; Transcription, Genetic/physiology

Significance

Annotations

Gene product Qualifier GO ID GO term name Evidence Code with/from Aspect Notes Status


See also

References

See Help:References for how to manage references in GONUTS.