Microtubules (MTs) are important cellular organelles that are structurally and functionally diverse. Moreover, different MTs are differentially sensitive to different depolymerizing agents and bind different MT associated proteins. It has been hypothesized that MT diversity may be caused by differences in the tubulin composition of MTs. Tubulin, the major structural protein of MTs, is composed of two subunits, alpha and beta tubulin. There are multiple genes for each of these subunits in all of the organisms that have been examined. Not only are there genetic isotypes of alpha and beta tubulin, but there are also posttranscriptionally modified tubulin isotypes, some of which have been shown to be localized to specific MT populations. In this application we propose to analyze the relationship between tubulin genetic isotypes and MT structure and function in the filamentous fungus Aspergillus nidulans. Three of the four Aspergillus tubulin genes, two beta tubulins and one alpha tubulin have been cloned and sequenced. The beta tubulins have been assigned to their genetic loci by DNA mediated integrative transformation, and the function of one of these genes has been examined by DNA mediated """"""""gene disruption."""""""" We propose to clone the remaining alpha tubulin gene, to use DNA mediated integrative transformation to assign the two as yet unassigned alpha tubulin sequences to their genetic loci and to use """"""""gene disruption"""""""" and in vitro mutagenesis to examine the functions of all of these genes. In addition we propose to use isotype specific antitubulin antibodies to localize specific tubulin to specific MTs by fluorescence immunocytochemistry and to construct chaemeric tubulin genes to determine whether tubulin genetic isotypes are interchangeable.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM029228-09
Application #
3276792
Study Section
Molecular Cytology Study Section (CTY)
Project Start
1981-06-01
Project End
1991-06-30
Budget Start
1989-07-01
Budget End
1990-06-30
Support Year
9
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Rutgers University
Department
Type
Schools of Pharmacy
DUNS #
038633251
City
New Brunswick
State
NJ
Country
United States
Zip Code
08901
Xiang, X; Osmani, A H; Osmani, S A et al. (1995) Analysis of nuclear migration in Aspergillus nidulans. Cold Spring Harb Symp Quant Biol 60:813-9
Beckwith, S M; Roghi, C H; Morris, N R (1995) The genetics of nuclear migration in fungi. Genet Eng (N Y) 17:165-80
Chiu, Y H; Morris, N R (1995) Extragenic suppressors of nudC3, a mutation that blocks nuclear migration in Aspergillus nidulans. Genetics 141:453-64
Willins, D A; Xiang, X; Morris, N R (1995) An alpha tubulin mutation suppresses nuclear migration mutations in Aspergillus nidulans. Genetics 141:1287-98
Kirk, K E; Morris, N R (1993) Either alpha-tubulin isogene product is sufficient for microtubule function during all stages of growth and differentiation in Aspergillus nidulans. Mol Cell Biol 13:4465-76
Morris, N R; Enos, A P (1992) Mitotic gold in a mold: Aspergillus genetics and the biology of mitosis. Trends Genet 8:32-7
Kirk, K E; Morris, N R (1991) The tubB alpha-tubulin gene is essential for sexual development in Aspergillus nidulans. Genes Dev 5:2014-23
Enos, A P; Morris, N R (1990) Mutation of a gene that encodes a kinesin-like protein blocks nuclear division in A. nidulans. Cell 60:1019-27
May, G S; Waring, R B; Morris, N R (1990) Increasing tubC beta-tubulin synthesis by placing it under the control of a benA beta-tubulin upstream sequence causes a reduction in benA beta-tubulin level but has no effect on microtubule function. Cell Motil Cytoskeleton 16:214-20
Osmani, S A; Engle, D B; Doonan, J H et al. (1988) Spindle formation and chromatin condensation in cells blocked at interphase by mutation of a negative cell cycle control gene. Cell 52:241-51

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