High impact information on SFP1

• These findings suggest that nutrient signals set the critical cell-size threshold via Sfp1 and Sch9-mediated control of ribosome biosynthetic rates [1].
• 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 [1].
• Additionally, cells lacking Sfp1 fail to appropriately modulate RP gene expression in response to environmental cues [2].
• We demonstrate that the Stp2 binding site also interacts genetically with Stp1, a regulator of amino acid permease genes and, with Sfp1, a key regulator of cell growth [3].
• The SFP1 gene product of Saccharomyces cerevisiae regulates G2/M transitions during the mitotic cell cycle and DNA-damage response [4].

Biological context of SFP1

• Disruption of the SFP1 gene results in slow cell growth, with cells having multiple, nucleated buds [5].
• It is designated SFP1 for split finger protein because its two zinc-finger domains are separated from one another by 40 amino acids (aa) as opposed to the usual spacing of 7 or 8 aa for Cys2His2 proteins [5].
• SFP1 is involved in cell size modulation in respiro-fermentative growth conditions [6].
• In a screening for mutants affected in cell size at Start, SFP1 has been identified as a gene whose deletion caused one of the smallest whi phenotype [6].
• In this study we show that SFP1 plays a role in ribosome biogenesis [7].

Associations of SFP1 with chemical compounds

• It follows that sfp1 cells growing on ethanol have a larger size than cells growing on glucose and, noticeably, the former enter the S phase with a critical cell size higher than the latter [6].

Regulatory relationships of SFP1

• In support of this model, overexpression of Sfp1p induces the expression of the PDS1 gene, which is known to encode a protein that regulates the G2 checkpoint [4].

Other interactions of SFP1

• Sfp1 and Sch9 are required for carbon-source modulation of cell size and are regulated at the level of nuclear localization and abundance, respectively [1].
• Ribosome biogenesis is intimately linked to cell size through Sfp1, a transcription factor that controls the expression of at least 60 genes implicated in ribosome assembly [8].

Analytical, diagnostic and therapeutic context of SFP1

• Microarray analysis has previously shown that ectopically expressed SFP1 induces the transcription of a large subset of genes involved in ribosome biogenesis [7].

References