Collart Martine A
Department of Medical Biochemistry, University of Geneva Medical School, 1211 4 Geneva, Switzerland.
Gene. 2003 Aug 14;313:1-16. doi: 10.1016/s0378-1119(03)00672-3.
The Ccr4-Not complex is a global regulator of gene expression that is conserved from yeast to human. It is a large complex that in the yeast Saccharmyces cerevisiae exists in two prominent forms of 0.9-1.2 and 1.9-2 MDa, and consists of at least nine core subunits: the five Not proteins (Not1p to Not5p), Caf1p, Caf40p, Caf130p and Ccr4p. It was initially described to be a global regulator of transcription, based upon the observation that the levels of many transcripts were increased or decreased in mutants. However, the recent finding that Caf1p and Ccr4p encode the major yeast deadenylase has suggested that this complex may additionally play a role in RNA degradation. In this review, the events that led to the identification of the Ccr4-Not complex are described and the elements that clearly demonstrate that the Ccr4-Not complex regulates many different cellular functions are discussed, including RNA degradation and transcription initiation. The evidence points to a role for the Ccr4-Not complex as a regulatory platform that senses nutrient levels and stress.
Ccr4-Not复合物是一种从酵母到人类都保守的基因表达全局调节因子。它是一个大型复合物，在酿酒酵母中以两种主要形式存在，分子量分别为0.9 - 1.2 MDa和1.9 - 2 MDa，至少由九个核心亚基组成：五个Not蛋白（Not1p至Not5p）、Caf1p、Caf40p、Caf130p和Ccr4p。最初，基于许多转录本在突变体中的水平升高或降低这一观察结果，它被描述为转录的全局调节因子。然而，最近发现Caf1p和Ccr4p编码酵母主要的去腺苷酸化酶，这表明该复合物可能在RNA降解中也发挥作用。在这篇综述中，描述了导致Ccr4-Not复合物被鉴定的事件，并讨论了清楚表明Ccr4-Not复合物调节许多不同细胞功能的因素，包括RNA降解和转录起始。证据表明Ccr4-Not复合物作为一个感知营养水平和应激的调节平台发挥作用。
