REGULATION OF THE TRANSCRIPTION FACTOR MET4

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 酵母转录激活剂Met4协调含硫化合物与细胞增殖的动态平衡。在正常生长条件下，Met4保持不活跃状态，但当细胞内S-腺苷甲硫氨酸水平不足，或者细胞遭受镉、砷胁迫时，Met4迅速激活。Met4控制一个转录程序，使S-腺苷蛋氨酸水平恢复，防止镉和砷胁迫对细胞的损伤，并诱导细胞周期停滞。 Met4的失活是通过蛋白降解实现的，而不依赖于多泛素化的调节。泛素连接酶SCF-Met30使Met4保持在泛素化的非活性状态。抑制SCF-Met30结合Met4去泛素化可迅速激活Met4以响应多种信号。 我们建议使用荧光显微镜来分析完整细胞中的Met4激活。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The yeast transcriptional activator Met4 coordinates homeostasis of sulfur-containing compounds with cell proliferation. Under normal growth conditions Met4 is maintained in an inactive state, but when the intracellular levels of S-adenosylmethionine are inadequate, or cells experience cadmium or arsenic stress, Met4 gets rapidly activated. Met4 controls a transcriptional program that restores S-adenosylmethionine levels, prevents cell damage by cadmium and arsenic stress, and induces a cell cycle arrest. Inactivation of Met4 is achieved by proteolysis-independent regulation by polyubiquitination. The ubiquitin ligase SCF-Met30 keeps Met4 in the ubiquitinated, inactive form. Inhibition of SCF-Met30 combined with Met4 deubiquitination rapidly activates Met4 in response to a variety of signals. We propose to use fluorescence microscopy to analyze Met4 activation in intact cells.