Genetic study of the role of calcium ions in the cell division cycle of Saccharomyces cerevisiae: A calcium-dependent mutant and its trifluoperazine-dependent pseudorevertants
✍ Scribed by Ohya, Yoshikazu ;Ohsumi, Yoshinori ;Anraku, Yasuhiro
- Publisher
- Springer
- Year
- 1984
- Tongue
- English
- Weight
- 652 KB
- Volume
- 193
- Category
- Article
- ISSN
- 0026-8925
No coin nor oath required. For personal study only.
✦ Synopsis
A cal1-1 mutant of the yeast Saccharomyces cerevisiae showing Ca2+-dependent growth was isolated. Its growth continued exponentially in Ca2+-rich medium, but stopped in Ca2+-poor medium at 37 degrees C. Mg2+ ions could not replace Ca2+ ions. In Ca2+-poor medium, the mutant cells stopped growing homogeneously at the stage of cell division cycle with a tiny bud. The nucleus in these arrested cells was in the G2 stage, judging from observation after nuclear staining and determination of the DNA content. Trifluoperazine-dependent pseudorevertants, which could grow in the presence of 20 microM to 80 microM trifluoperazine in Ca2+-poor medium at 37 degrees C, were obtained from this cal1-1 mutant. The suppressor mutation, tfr1, itself conferred trifluoperazine resistance. Other calmodulin inhibitors structurally unrelated to trifluoperazine had similar effects to trifluoperazine on these pseudorevertants. These results suggest that Ca2+ ions and a calmodulin play important roles in the yeast cell division cycle at the stage of bud growth and nuclear division.