The two [alpha]-tubulin isotypes in budding yeast have opposing effects on microtubule dynamics in vitro

• Published in: EMBO reports 2003-01, Vol.4 (1), p.94
• Main Authors: Bode, Claudia J, Gupta, Mohan L, Suprenant, Kathy A, Himes, Richard H
• Format: Article
• Language: English
• Subjects: Yeasts
• ISSN: 1469-221X; 1469-3178
• DOI: 10.1038/sj.embor.embor716

The yeast Saccharomyces cerevisiae has two genes for alpha-tubulin, TUB1 and TUB3, and one beta-tubulin gene, TUB2. The gene product of TUB3, Tub3, represents approximately 10% of alpha-tubulin in the cell. We determined the effects of the two alpha-tubulin isotypes on microtubule dynamics in vitro. Tubulin was purified from wild-type and deletion strains lacking either Tub1 or Tub3, and parameters of microtubule dynamics were examined. Microtubules containing Tub3 as the only alpha-tubulin isotype were less dynamic than wild-type microtubules, as shown by a shrinkage rate and catastrophe frequency that were about one-third of that for wild-type microtubules. Conversely, microtubules containing Tub1 as the only alpha-tubulin isotype were more dynamic than wild-type microtubules, as shown by a shrinkage rate that was 50% higher and a catastrophe frequency that was 30% higher than those of wild-type microtubules. The results suggest that a role of Tub3 in budding yeast is to control microtubule dynamics.