遗传 ›› 2013, Vol. 35 ›› Issue (8): 1030-1039.doi: 10.3724/SP.J.1005.2013.01030

• 研究报告 • 上一篇    下一篇

裂殖酵母Cnb1参与胞质分裂过程

范洁琼, 邓小龙, 冯碧薇, 王继峰, 余垚, 吕红   

  1. 复旦大学生命科学学院, 遗传工程国家重点实验室, 上海 200433
  • 收稿日期:2013-03-05 修回日期:2013-04-19 出版日期:2013-08-20 发布日期:2013-08-25
  • 通讯作者: 吕红 E-mail:honglv@fudan.edu.cn
  • 基金资助:

    国家重点基础研究发展计划(973计划)项目(编号:2009CB825601)和国家自然科学基金项目(编号:31200961)资助

Cnb1 involved in cytokinesis in Schizosaccharomyces pombe

FAN Jie-Qiong, DENG Xiao-Long, FENG Bi-Wei, WANG Ji-Feng, YU Yao, LV Hong   

  1. State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China
  • Received:2013-03-05 Revised:2013-04-19 Online:2013-08-20 Published:2013-08-25

摘要:

丝/苏氨酸特异性钙调磷酸酶(Calcineurin, CN)是一种在真核生物中广泛存在的蛋白, 是参与转录调控的重要分子。裂殖酵母中的CN是由催化亚基Ppb1和调节亚基Cnb1组成的异源二聚体。文章报道了裂殖酵母中cnb1+的缺失引起细胞生长速度缓慢, 产生多隔膜现象, 胞质分裂受阻滞。胞质分裂过程中, Cnb1与Ppb1组成CN复合物, 与收缩环在分裂平面上共定位, 并与收缩环一起收缩。cnb1Δ菌株的隔膜成熟过程存在缺陷, 微管出现纵穿隔膜的现象。上述结果说明Cnb1可能参与隔膜的成熟过程。此外, 还检测了cnb1D菌株中胞裂蛋白的信号。胞裂蛋白包括Spn1、Spn2、Spn3和Spn4, 它们是引导隔膜降解的重要分子。结果显示, 在cnb1D菌株中, 80%左右的细胞在隔膜处缺失Spn2和Spn3的信号, 20%左右的细胞缺失Spn1和Spn4的信号。由于胞裂蛋白的蛋白表达量在cnb1D中没有降低, 因此胞裂蛋白信号的消失不是转录缺陷引起的, 这暗示Cnb1可能采用了不依赖转录的方式来调控胞裂蛋白环的稳定性。以上结果提示, Cnb1可能通过影响隔膜的成熟及胞裂蛋白环的稳定性参与调节裂殖酵母的胞质分裂过程。

关键词: Cnb1, 胞质分裂, 收缩环, 裂殖酵母, 胞裂蛋白

Abstract:

Serine/Threonine-specific calcineurin (CN) is highly conserved in eukaryotes, which plays an important role in transcriptional regulation. In Schizosaccharomyces pombe, CN exists as a heterodimer composed by catalytic subunit Ppb1 and regulatory subunit Cnb1. Deletion of cnb1+ reduced the growth rate of cells, and caused a chained phenotype, and had delay in cytokinesis. In cytokinesis, Cnb1 could form CN complex with Ppb1 and could colocalize and constrict with the contractile ring at division plane. Tubulin could cross the septum in cnb1Δ strain, suggesting that the septum is not fully matured. These results suggest Cnb1 might be involved in maturation of septum. The signals of septins in cnb1Δ strain were also analyzed. Septins include Spn1, Spn2, Spn3, and Spn4. Septins help to guide hydrolytic enzymes for septum degrada-tion. Eighty percent of cnb1Δ cells lacked the signals of Spn2 or Spn3 at septum, and twenty percent of cnb1Δ cells lacked the signals of Spn1 or Spn4 at septum. The reduction of the septin signals was not due to impaired transcription of septins, since the protein levels of septins in the cnb1Δ cells were not decreased. These results imply that Cnb1 might regulate the stability of septin ring in a transcription-independent manner. In general, our study showed that Cnb1 contributes to the maturation of septum and the stability of septin ring and is important in the cytokinesis.

Key words: cytokinesis, septin, contractile ring, Schizosaccharomyces pombe, Cnb1