STU1, A SUPPRESSOR OF A BETA-TUBULIN MUTATION, ENCODES A NOVEL AND ESSENTIAL COMPONENT OF THE YEAST MITOTIC SPINDLE

Citation
D. Pasqualone et Tc. Huffaker, STU1, A SUPPRESSOR OF A BETA-TUBULIN MUTATION, ENCODES A NOVEL AND ESSENTIAL COMPONENT OF THE YEAST MITOTIC SPINDLE, The Journal of cell biology, 127(6), 1994, pp. 1973-1984
Citations number
40
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell Biology
Journal title
ISSN journal
0021-9525
Volume
127
Issue
6
Year of publication
1994
Part
2
Pages
1973 - 1984
Database
ISI
SICI code
0021-9525(1994)127:6<1973:SASOAB>2.0.ZU;2-G
Abstract
We have isolated a cold-sensitive allele of TUB2, the sole gene encodi ng beta-tubulin in S. cerevisiae, that confers a specific defect in sp indle microtubule function. At 14 degrees C, tub2-406 cells lack a nor mal bipolar spindle but do assemble functional cytoplasmic microtubule s. In an attempt to identify proteins that are important for spindle a ssembly, we screened for suppressors of the cold-sensitivity of tub2-4 06 and obtained four alleles of a novel gene, STU1. Genetic interactio ns between stu1 alleles and alleles of TUB1 and TUB2 suggest that Stu1 p specifically interacts with microtubules. STU1 is essential for grow th and disruption of STU1 causes defects in spindle assembly that are similar to those produced by the tub2-406 mutation. The nucleotide seq uence of the STU1 gene predicts a protein product of 174 kD with no si gnificant similarity to known proteins. An epitope-tagged Stu1p coloca lizes with microtubules in the mitotic spindle of yeast. These results demonstrate that Stu1p is an essential component of the yeast mitotic spindle.