Down-regulation of Cdk1 activity in G1 coordinates the G1/S gene expression programme with genome replication
Cell division is regulated by cyclin-dependent kinases (Cdks) and requires the periodic activation and inactivation of transcription factors that generate waves of gene expression in different cell-cycle phases. In fission yeast, the MCB-binding transcription factor (MBF) is activated at the end of G1 and regulates the expression of a set of genes that encode for proteins involved in the G1/S transition and DNA replication. Here, we review the importance of controlling MBF by Cdk activity at the onset of S phase. Furthermore, we emphasize that MBF regulation by Cdk is particularly critical under conditions in which G1 is extended, such as in nitrogen-poor environments, where down-regulation of Cdk activity in G1 is crucial to generate a proper wave of MBF-dependent transcription at the end of G1, which is critical to promote a successful S phase.
KeywordsCell cycle G1/S transcription MBF CDK inhibition Rum1 Ste9 Genomic instability dNTPs Nitrogen TORC2 Gad8
We thank members of the Moreno’s lab for discussions. This work was supported by Grants from the Ministerio de Economía y Competitividad (BFU2017-88335-R) and Junta de Castilla y León (CSI084U16 and CLU-2017-03). NG-B is the recipient of the FPU15/03654 predoctoral training grant from the Ministerio de Educación, Cultura y Deporte.
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