Related Experiment Video

Updated: Aug 12, 2026

Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations
10:54

Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations

Published on: September 17, 2012

Mutational analysis of Cak1p, an essential protein kinase that regulates cell cycle progression

K T Chun1, M G Goebl

  • 1Walther Oncology Center, Indiana University School of Medicine, Indianapolis 46202-5122, USA.

Molecular & General Genetics : MGG
|December 11, 1997
PubMed

Insights

The CAK1 gene is essential for cell cycle progression in Saccharomyces cerevisiae. Mutations in CAK1 prevent the activation of Cdc28p, leading to cell cycle arrest.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • Entry into S phase in Saccharomyces cerevisiae necessitates Cdc28p activation via cyclins Clb5p/Clb6p and Sic1p degradation.
  • Defects in this activation lead to cell cycle arrest post-START, characterized by unreplicated DNA and elongated buds.

Purpose of the Study:

  • To investigate the role of the CAK1 gene in Saccharomyces cerevisiae cell cycle progression.
  • To characterize the function of the Cak1p protein kinase.

Main Methods:

  • Analysis of CAK1 gene mutations and their effect on cell cycle progression.
  • In vitro kinase assays to assess Cak1p autophosphorylation and Cdc28p phosphorylation.
  • Complementation studies using CAK1 deletion mutants.

Main Results:

  • Mutations in CAK1 cause inviability and cell cycle arrest with a single nucleus and multiple, elongated buds.
  • CAK1 encodes a protein kinase related to the Cdc2p family.
  • Inactive Cak1p kinase mutants cannot rescue CAK1 deletion mutants, highlighting the importance of kinase activity.

Conclusions:

  • Cak1p protein kinase activity is crucial for cell cycle progression in Saccharomyces cerevisiae.
  • CAK1 is a novel gene involved in the S phase entry pathway, alongside CDC4, CDC34, CDC53, and CLB genes.

More Related Videos

Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk113:15

Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk1

Published on: February 25, 2016

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay12:26

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Published on: May 3, 2018

Related Concept Videos

Positive Regulator Molecules01:45

Positive Regulator Molecules

To consistently produce healthy cells, the cell cycle—the process that generates daughter cells—must be precisely regulated.
DNA Damage can Stall the Cell Cycle02:36

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
Positive Regulator Molecules02:39

Positive Regulator Molecules

Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
M-Cdk Drives Transition Into Mitosis02:15

M-Cdk Drives Transition Into Mitosis

Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
Anaphase Promoting Complex00:50

Anaphase Promoting Complex

The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...