UBIQUITIN AND YEAST CD34 GENE FUNCTION

泛素偶联蛋白--酿酒酵母的CDC34蛋白 酶，可以进行自素化。反应产物是一种 多泛素化的CDC34蛋白。多泛素链的连接 通常是选择性降解蛋白质的信号 蛋白。对于cdc34蛋白是否如此，这是一个 拟开展的研究。我们建议确定自动素化位点 然后通过体外诱变将这些位点改变为 产生自身素化缺陷的突变体。然后我们将表示这些 突变株在酿酒酵母中的检测 自动素化作用于靶向CDC34蛋白的降解和 这种降级是否对控制可获得性很重要 CDC34蛋白在细胞周期中的表达。最后，我们将进一步定义 CDC34通过鉴定和鉴定蛋白的生化作用 与CDC34蛋白相互作用，或者作为多蛋白的参与者 络合物或作为cdc34依赖泛素化的底物。这些 研究将导致对泛素化作用的重要见解 在控制细胞生长方面。

Cdc34 protein of Saccharomyces cerevisiae, a ubiquitin conjugating enzyme, can undergo autoubiquitination. The reaction product is a multiubiquitinated Cdc34 protein. Attachment of a multiubiquitin chain to a protein is usually a signal for selective degradation of that protein. Whether this is the case for Cdc34 protein is a subject of the proposed research. We propose to identify the autoubiquitination sites in Cdc34 protein and then alter these sites by in vitro mutagenesis to generate autoubiquitination-defective mutants. We will then express these mutants in Saccharomyces cerevisiae to determine whether autoubiquitination serves to target Cdc34 protein for degradation and whether such degradation is important in controlling the availability of Cdc34 protein during the cell cycle. Finally, we will further define the biochemical role of CDC34 by identifying and characterizing proteins that interact with Cdc34 protein, either as participants in a multiprotein complex or as substrates for Cdc34-dependent ubiquitination. These studies will lead to important insights into the role of ubiquitination in the control of cell growth.