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Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay
Published on: May 3, 2018
Pch1(+), a second essential C-type cyclin gene in Schizosaccharomyces pombe
B A Furnari1, P Russell, J Leatherwood
1Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
The Journal of Biological Chemistry
|May 2, 1997
Summary
The essential Schizosaccharomyces pombe gene pch1(+) encodes a C-type cyclin. Loss of Pch1 causes inviability and morphological defects, highlighting its critical role in cell viability.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Cyclins regulate cell cycle progression in eukaryotes.
- C-type cyclins are a distinct class of cyclins with conserved functions.
- Schizosaccharomyces pombe is a model organism for studying cell cycle control.
Purpose of the Study:
- To isolate and characterize novel proteins interacting with Cdc2 in S. pombe.
- To investigate the function and regulation of the Pch1 protein, a novel C-type cyclin homolog.
- To determine the essentiality and cellular roles of Pch1 in S. pombe.
Main Methods:
- Two-hybrid screening to identify interacting proteins.
- Co-immunoprecipitation to confirm protein interactions.
- Kinase assays using purified Pch1-associated kinase.
- Analysis of pch1 mRNA levels during the cell cycle.
- Phenotypic analysis of Deltapch1 deletion mutants.
Main Results:
- Pch1, a novel S. pombe C-type cyclin, interacts with Cdc2.
- Pch1-associated kinase phosphorylates myelin basic protein, histone H1, and RNA polymerase II.
- pch1 mRNA levels do not oscillate during the cell cycle.
- Deltapch1 cells are inviable, exhibiting morphological defects and growth deficiency.
- Loss of Pch1 function does not cause a cdc cell cycle arrest phenotype.
Conclusions:
- Pch1 is an essential C-type cyclin in S. pombe, crucial for cell viability.
- Pch1 plays a role in cellular processes beyond cell cycle progression, indicated by morphological defects.
- S. pombe possesses two essential C-type cyclins, Pch1 and Mcs2, with distinct roles.
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