Eukaryotic Cell Cycle Control

本研究的目的是了解控制细胞周期“启动”和细胞分化“启动”的分子机制。为此，已将裂殖酵母作为模式生物进行了研究，因为这种生物与高等真核生物密切相关。在过去的3年中，我们发现了4个控制分化开始的新因子和5个控制细胞周期“开始”的新因子。在这4个因子中，B型细胞周期蛋白负控制分化的开始和正控制细胞周期的开始;称为Phh 1的应激信号MAP激酶正控制分化的开始;一种名为Rcd 1的新蛋白，对氮饥饿诱导的分化开始至关重要; Nrd 1，一种负控制分化开始的RNA结合蛋白。在5个细胞周期“启动”因子中，Res 2是与Cdc 10形成转录因子复合物的DNA结合亚基，Rep 1和Rep 2是通过与Res 2-Cdc 10形成复合物起作用的两个转录激活子亚基，Rep 1和Rep 2是通过与Cdc 10形成复合物起作用的两个转录激活子亚基，Rep 1和Rep 2是通过与Cdc 10形成复合物起作用的两个转录激活子亚基。新的细胞周期蛋白Pas 1与Cdc 2激酶相关并激活Res 2/Cdc 10/Rep 2; Spt 1是一种新的结合Cdc 18并关键控制S期的发生和进展的因子。Spt 1可能形成独立于Cdc 2/Pas 1-Res/Cdc 10/Rep-Cdc 18级联的控制级联。

The goal of this research is to understand the molecular mechanism controlling the cell cycle "start" and the cell differentiation "start". To this end, fission yeast has been studied as a model organism because this organism is closely related to higher eukaryotes. During the past 3 years, we have discovered 4 novel factors controlling the onset of differentiation and 5 new factors controlling the cell cycle "start". Among the 4 factors are a B-type cyclin that negatively controls the onset of differentiation and positively controls the start of the cell cycle ; a stress signal MAP kinase called Phh1 that positively controls the onset of differentiation ; a novel protein named Rcd1 that is essential for nitrogen-starvation-induced start of differentiation ; Nrd1, a RNA binding protein that negatively controls the onset of differentiation. They have mammalian homologues, raising the possibility that the differentiation control system found in fission yeast may be conserved up to mammals.Among the 5 cell cycle "start" factors are Res2, a DNA binding subunit that forms a transcriptional factor complex with Cdc10 ; Rep1 and Rep2, two transcriptional activator subunits that act by forming a complex with Res2-Cdc10 ; the new cyclin Pas1 that associates with Cdc2 kinase and activates Res2/Cdc10/Rep2 ; Spt1 a novel factor that binds Cdc18 and critically controls the onset and progression of S phase. Spt1 might form a control cascade independent of the Cdc2/Pas1-Res/Cdc10/Rep-Cdc18 cascade.