The isolation and characterization of microtubule mutants using drug-resistance selections has provided insights into the role of microtubules in mitosis, the mechanism of drug-resistance in mammalian cells, and regulatory mechanisms in microtubule assembly. Recently, methods have been devised which enhance our ability to isolate mutants; and ideas on how to use mutants to study microtubule function, assembly, and regulation have been refined. Using this information, we propose to isolate many new mutants to determine the range of mutant phenotypes and to test developing ideas on the mechanism of drug action and cellular mechanisms of resistance to their effects. Considerable effort will be devoted toward the development of new selections for obtaining mutants in microtubule assembly and in the expression of microtubule associated proteins (MAPs). We already have one mutant of the first type and believe we may have one of the second. At the same time it will be necessary to develop tools to fully characterize these mutants. Included in these studies will be the isolation and characterization of the spindle apparatus from CHO cells, the identification of MAPs, and the generation of antibodies against various MAP and spindle components. This work should complement and extend our current knowledge of microtubule physiology and provide a basis for understanding drug action and cellular mechanisms of resistance.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA052962-11
Application #
3197801
Study Section
Molecular Cytology Study Section (CTY)
Project Start
1990-05-01
Project End
1995-04-30
Budget Start
1992-05-01
Budget End
1993-04-30
Support Year
11
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Texas Health Science Center Houston
Department
Type
Schools of Medicine
DUNS #
City
Houston
State
TX
Country
United States
Zip Code
77225
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Yu, X C; Margolin, W; Gonzalez-Garay, M L et al. (1999) Vinblastine induces an interaction between FtsZ and tubulin in mammalian cells. J Cell Sci 112 ( Pt 14):2301-11
Gonzalez-Garay, M L; Chang, L; Blade, K et al. (1999) A beta-tubulin leucine cluster involved in microtubule assembly and paclitaxel resistance. J Biol Chem 274:23875-82
Boggs, B A; Gonzalez-Garay, M L; Cabral, F (1996) Significant divergence in nucleotide sequences for beta-tubulin from different laboratory strains of Chinese hamster ovary cells. DNA Seq 6:171-4
Gonzalez-Garay, M L; Cabral, F (1996) alpha-Tubulin limits its own synthesis: evidence for a mechanism involving translational repression. J Cell Biol 135:1525-34
Gonzalez-Garay, M L; Cabral, F (1995) Overexpression of an epitope-tagged beta-tubulin in Chinese hamster ovary cells causes an increase in endogenous alpha-tubulin synthesis. Cell Motil Cytoskeleton 31:259-72
Barlow, S; Gonzalez-Garay, M L; West, R R et al. (1994) Stable expression of heterologous microtubule-associated proteins (MAPs) in Chinese hamster ovary cells: evidence for differing roles of MAPs in microtubule organization. J Cell Biol 126:1017-29
Dahllof, B; Billstrom, A; Cabral, F et al. (1993) Estramustine depolymerizes microtubules by binding to tubulin. Cancer Res 53:4573-81
Minotti, A M; Barlow, S B; Cabral, F (1991) Resistance to antimitotic drugs in Chinese hamster ovary cells correlates with changes in the level of polymerized tubulin. J Biol Chem 266:3987-94