Ana Kitazono

Keywords:

Cell cycle regulation; mitosis, checkpoints; cyclin-dependent kinases

Research Area:

Regulation of mitosis by the Cdc28 cyclin-dependent kinase (CDK); Cdc28 (Cdc2/Cdk1) phosphorylates specific substrates

Description of Research:

How do cells regulate their growth and division? What are the molecular mechanisms behind this regulation? What happens when these mechanisms are not working properly? These are the main questions that motivate our research, using the bakers’ yeast Saccharomyces cerevisiae. This system allows us to employ a wide array of genetic, cell biological and biochemical techniques, taking advantage of the abundant resources available (markers for selection, variety of vectors and inducible promoters, genome databases, genomic DNA libraries for expression and to perform genetic screens, libraries for genomic and proteomic studies, etc.). Further, since most cell cycle mechanisms are remarkably conserved, findings in yeast are relevant towards understanding how human cells regulate their growth.

Currently, we are focusing our studies in the regulation of mitosis by the Cdc28 cyclin-dependent kinase (CDK), the main regulator of the yeast cell cycle. Cdc28 (Cdc2/Cdk1) phosphorylates specific substrates in a timely manner and requires for activity binding of different cyclin subunits, which determine the specificity and localization of the complexes. Activation of Cdc28 also requires phosphorylation by the Cak1 kinase and binding of the Cks1 subunit. We found that mutations at the carboxyl-terminus of Cdc28 result in inappropriate mitotic progression and high levels of chromosome instability. Interestingly, presence of high copy numbers of Cak1 suppresses these phenotypes independently of its catalytic activity, suggesting that the carboxyl-terminus of Cdc28 is essential for binding. We are currently analyzing the nature of this interaction and its effect on Cdc28 activity and the regulation of mitotic progression.

Contact Information

Ana Kitazono
Molecular Genetics and Systems Biology
Assistant Professor, Department of Biochemistry, Cellular & Molecular Biology

UT
F225 Walters Life Sciences
1414 W. Cumberland Ave.
Knoxville, TN 37996
865-974-3149

Email: akitazon@utk.edu

Degrees