Schizosaccharomyces pombe Calmodulin, Cam1, Plays a Crucial Role in Sporulation by Recruiting and Stabilizing the Spindle Pole Body Components Responsible for Assembly of the Forespore Membrane
Schizosaccharomyces pombe Calmodulin, Cam1, Plays a Crucial Role in Sporulation by Recruiting and Stabilizing the Spindle Pole Body Components Responsible for Assembly of the Forespore Membrane
复制标题
DOI：
10.1128/ec.00022-10
复制
发表时间：
2010-12-01
期刊：
影响因子：
--
通讯作者：
Shimoda, Chikashi
中科院分区：
文献类型：
--
作者：
Itadani, Akiko;Nakamura, Taro;Shimoda, Chikashi
粟酒裂殖酵母中的钙调素由cam1（+）基因编码，其对于营养生长和孢子形成都是不可缺少的。在这里，我们报告了Cam1在孢子形成中的功能。我们发现Cam1在减数分裂和孢子形成过程中优先定位于纺锤体极体（SPB）。前孢子膜的形成，在孢子中质膜的前体，被阻止在一个错义cam1突变体，这是可行的，但不能形成孢子。三个SPB蛋白质的发病所需的前孢子膜形成，Spo2，Spo13，Spo15，不能本地化的SPB在cam1突变体，虽然五个核心SPB组件进行了测试。已知Spo2和Spo13的募集需要SPB中存在Spo15。值得注意的是，Spo15在cam1突变体中不稳定，因此Spo2和Spo13的SPB定位丢失。Spo15的过表达部分缓解了cam1突变体中的孢子形成缺陷。这些结果表明，钙调蛋白在前孢子膜的形成中起着重要的作用，通过稳定地维持Spo15，从而Spo2和Spo13，在减数分裂细胞的SPB。
Calmodulin in Schizosaccharomyces pombe is encoded by the cam1(+) gene, which is indispensable for both vegetative growth and sporulation. Here, we report how Cam1 functions in spore formation. We found that Cam1 preferentially localized to the spindle pole body (SPB) during meiosis and sporulation. Formation of the forespore membrane, a precursor of the plasma membrane in spores, was blocked in a missense cam1 mutant, which was viable but unable to sporulate. Three SPB proteins necessary for the onset of forespore membrane formation, Spo2, Spo13, and Spo15, were unable to localize to the SPB in the cam1 mutant although five core SPB components that were tested were present. Recruitment of Spo2 and Spo13 is known to require the presence of Spo15 in the SPB. Notably, Spo15 was unstable in the cam1 mutant, and as a result, SPB localization of Spo2 and Spo13 was lost. Overexpression of Spo15 partially alleviated the sporulation defect in the cam1 mutant. These results indicate that calmodulin plays an essential role in forespore membrane formation by stably maintaining Spo15, and thus Spo2 and Spo13, at the SPB in meiotic cells.