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Manipulation and Analysis of Cell Cycle-Dependent Processes in Budding Yeast
Published on: September 26, 2025
Pho85, a multifunctional cyclin-dependent protein kinase in budding yeast
Dongqing Huang1, Helena Friesen, Brenda Andrews
1Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.
Molecular Microbiology
|September 14, 2007
Summary
Pho85, a cyclin-dependent kinase (Cdk) in yeast, regulates cell cycle and signaling pathways. Its diverse functions are mediated by various cyclins (Pcls), impacting gene expression, growth, and stress responses.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Pho85 is a multifunctional cyclin-dependent kinase (Cdk) in Saccharomyces cerevisiae.
- It plays crucial roles in cell cycle control and various cellular processes.
- Pho85 activity is regulated by 10 different cyclins, known as Pcls ( Pho85-associated cyclins).
Purpose of the Study:
- To elucidate the diverse roles of Pho85 in Saccharomyces cerevisiae.
- To understand how Pho85, through its associated cyclins, regulates cell cycle progression, gene expression, and cellular signaling.
- To explore the involvement of Pho85 in maintaining cellular homeostasis and responding to environmental conditions.
Main Methods:
- Utilized genetic screens, including synthetic lethality and synthetic dosage lethality.
- Employed proteomic screens to identify in vitro substrates of Pho85.
- Investigated the roles of specific Pho85-Pcl complexes in G1 phase and signaling pathways.
Main Results:
- Identified specific roles for three Pcls in G1 phase, regulating gene expression and polarized growth.
- Observed overlapping functions between Pho85 and Cln-Cdc28 in phosphorylating G1 substrates.
- Revealed that Pho85 is active under favorable conditions, phosphorylating transcription and regulatory proteins to suppress stress responses.
Conclusions:
- Pho85 is a versatile kinase with distinct functions mediated by different Pcls.
- Pho85 plays critical roles in both cell cycle progression and environmental sensing.
- Recent genetic and proteomic studies have expanded our understanding of Pho85's regulatory network and cellular functions.
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