Eukaryotic Cell doi:10.1128/EC.00283-07
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
Requirement of the budding yeast polo kinase Cdc5 in proper microtubule growth and dynamics
Chong J. Park,
Jung-Eun Park,
Tatiana S. Karpova,
Nak-Kyun Soung,
Li-Rong Yu,
Sukgil Song,
Kyung H. Lee,
Xue Xia,
Eugene Kang,
Ilknur Dabanoglu,
Doo-Yi Oh,
James Y. Zhang,
Young-Hwi Kang,
Stephen Wincovitch,
Tim C. Huffaker,
Timothy D. Veenstra,
James G. McNally,
and
Kyung S. Lee*
Laboratory of Metabolism, Laboratory of Receptor Biology and Gene Expression, Laboratory of Experimental Carcinogenesis, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Laboratory of Proteomics and Analytical Technologies, Advanced Technology Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
* To whom correspondence should be addressed. Email:
kyunglee{at}mail.nih.gov.
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Abstract |
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In many organisms, polo kinases appear to play multiple roles during M-phase progression. To provide new insights into the function of the budding yeast polo kinase Cdc5, we generated novel temperature-sensitive cdc5 mutants by mutagenizing the C-terminal non-catalytic polo-box domain (PBD), a region that is critical for proper subcellular localization. One of these mutants, cdc5-11, exhibited a temperature-sensitive growth defect with an abnormal spindle morphology. Strikingly, provision of a moderate level of benomyl, a microtubule depolymerizing drug, permitted cdc5-11 cells to grow significantly better than the isogenic CDC5 wild-type in a FEAR (cdc Fourteen Early Anaphase Release)-independent manner. In addition, cdc5-11 required MAD2 for both cell growth and benomyl-remedial phenotype. These results suggest that cdc5-11 is defective in proper spindle function. Consistent with this view, cdc5-11 exhibited abnormal spindle morphology, shorter spindle length, and delayed microtubule regrowth at the non-permissive temperature. Overexpression of CDC5 moderately rescued the spc98-2 growth defect. Interestingly, both Cdc28 and Cdc5 were required for proper modification of spindle pole body (SPB) components, Nud1, Slk19, and Stu2, in vivo. They also phosphorylated these three proteins in vitro. Taken together, these observations suggest that concerted action of Cdc28 and Cdc5 on Nud1, Slk19, and Stu2 is important for proper spindle functions.
