Analysis of regulation of the eukaryotic cell cycle.
The focus of the laboratory is to understand, analyze, and study the regulation of eukaryotic cell growth and division. The work is carried forward in a number of directions:
- The control of phosphorylation of the retinoblastoma protein is being analyzed under conditions where the normal division cycle is analyzed and perturbations of the cell cycle are minimized. We find that contrary to current belief, a phosphorylation-dephosphorylation of the Rb protein is not required during the mammalian division cycle. See Cooper, Yu, and Shayman, IUBMB (1999), and Cooper and Shayman. Cell and Molecular Life Sciences (2001) below.
- Time lapse videography is being pursued in order to analyze the methods currently being used to synchronize cells. Our results indicate that various starvation and inhibition methods do not synchronize cells. These results support theoretical analyses of synchronization methods. See Cooper, Cell Biology International (2002) below.
- We are studying the expression of BRCA1 protein during the division cycle and its phosphorylation pattern in order to understand how it is regulated during the division cycle.
- We are studying the expression of various cyclins during the normal division cycle in order to reexamine the current view of cyclin biogenesis and control. We are comparing results from two-color flow cytometric analysis with direct biochemical analysis in order to see whether localization of cyclins can account for the observed results.
- We are reanalyzing publicly available data from Microarray analysis in order to see whether proposals of G1-phase gene expression are statistically significant. See Shedden and Cooper, PNAS (2002) and Shedden and Cooper, Nucleic Acids Research (2002) below.
Shedden, K. and Cooper, S. 2002. Analysis of Cell-Cycle-Specific Gene Expression in Human Cells as Determined by Microarrays. Proc. Natl. Acad.Sci. USA 99:4379-4384.
Cooper, S. 2002. Reappraisal of G1-phase arrest and synchronization by lovastatin. Cell Biol. Int. 27:715-727.
Cooper, S. 2002. Minimally Disturbed, Multi-Cycle, and Reproducible Synchrony using a Eukaryotic "Baby Machine" Bioessays. 24:499-501
Shedden, K. and Cooper, S. 2002. Analysis of Cell-Cycle Gene Expression in S. cerevisiae Using Microarrays and Multiple Synchronization Methods. Nucleic Acids Research. 30:2920-2929.
Cooper, S. 2001. Revisiting the Relationship of the Mammalian G1 Phase to Cell Differentiation. J. Theor. Biol. 208:399-402.
In addition to these papers, much of this work is analyzed in detail in the book:
Cooper, S. Bacterial Growth and Division, Biochemistry and Regulation of Prokaryotic and Eukaryotic Division Cycles, Academic press. 1991.