Comparison of the Saccharomyces cerevisiae G1 cyclins: Cln3 may be an upstream activator of Cln1, Cln2 and other cyclins

Tyers, M., Tokiwa, G., Futcher, B. (May 1993) Comparison of the Saccharomyces cerevisiae G1 cyclins: Cln3 may be an upstream activator of Cln1, Cln2 and other cyclins. Embo J, 12 (5). pp. 1955-68. ISSN 0261-4189 (Print)

Abstract

In the budding yeast Saccharomyces cerevisiae, the G1 cyclins Cln1, Cln2 and Cln3 regulate entry into the cell cycle (Start) by activating the Cdc28 protein kinase. We find that Cln3 is a much rarer protein than Cln1 or Cln2 and has a much weaker associated histone H1 kinase activity. Unlike Cln1 and Cln2, Cln3 is not significantly cell cycle regulated, nor is it down-regulated by mating pheromone-induced G1 arrest. An artificial burst of CLN3 expression early in G1 phase accelerates Start and rapidly induces at least five other cyclin genes (CLN1, CLN2, HCS26, ORFD and CLB5) and the cell cycle-specific transcription factor SWI4. In similar experiments, CLN1 is less efficient than CLN3 at activating Start. Strikingly, expression of HCS26, ORFD and CLB5 is dependent on CLN3 in a cln1 cln2 strain, possibly explaining why CLN3 is essential in the absence of CLN1 and CLN2. To explain the potent ability of Cln3 to activate Start, despite its apparently weak biochemical activity, we propose that Cln3 may be an upstream activator of the G1 cyclins which directly catalyze Start. Given the large number of known cyclins, such cyclin cascades may be a common theme in cell cycle control.

Item Type: Paper
Uncontrolled Keywords: Base Sequence Comparative Study Cyclins/genetics/ metabolism Fungal Proteins/genetics/ metabolism G1 Phase Gene Expression Regulation, Fungal Molecular Sequence Data Mutation Oligodeoxyribonucleotides Peptides/metabolism Protamine Kinase/metabolism RNA, Messenger/metabolism Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. Saccharomyces cerevisiae/cytology/genetics/ metabolism Saccharomyces cerevisiae Proteins Trans-Activation (Genetics) Transcription, Genetic
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > Cyclins
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > transcription
organs, tissues, organelles, cell types and functions > cell types and functions > cell functions > cell cycle
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > genes, structure and function > gene expression
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > genes, structure and function > gene regulation
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > genes, structure and function > gene regulation
organism description > yeast
CSHL Authors:
Communities: CSHL labs > Futcher lab
Depositing User: Matt Covey
Date: May 1993
Date Deposited: 19 Apr 2016 19:43
Last Modified: 19 Apr 2016 19:43
PMCID: PMC413417
URI: https://repository.cshl.edu/id/eprint/32506

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