SNF/SWI COMPLEX AND TRANSCRIPTIONAL ACTIVATION

转录激活涉及基因- 特异性激活剂、一般转录装置和染色质。 在酿酒酵母中，SNF/SWI复合物具有重要的生物学活性。 在这一过程中的作用，并需要转录激活 不同的基因 SNF/SWI复合物通过基因特异性的 调节蛋白，并参与重塑染色质， 克服染色质介导的阻遏。 综合体由11个 蛋白质（包括SWI 1/ADR 6、SNF 2/SWI 2、SWI 3、SNF 5、SNF 6和SNF 11）和 在真核生物中被广泛保守。 同源蛋白质已经被 在果蝇和哺乳动物中发现了类似的复合物， 从人类中净化。 在酵母系统中，遗传方法可以被 应用于提供洞察生理上的重要功能， SVF/SWI复合体。 本建议侧重于分析以下方面的相互作用： 与体内其他蛋白质的复合物。 三个项目涉及 在先前的双杂交中鉴定的蛋白质的功能表征 筛选与SNF 2的相互作用。 第一种相互作用的蛋白质， MSN 1是基因特异性转录因子之间衔接子的候选者， 激活剂和SNF/SWI复合物。 对MSN 1的深入分析将是 来测试这个模型。 第二，基因编码的催化 cAMP依赖性蛋白激酶的亚基在双杂交中被回收。 筛选，以及这种激酶活性与SNF/SWI复合物的关系 将被评估。 第三，七种尚未鉴定的相互作用蛋白质 将以获得对SNF/SWI的新见解为目标 功能 最后，分析了这些机构的功能和相互作用， SNF 6蛋白将被启动。 遗传学证据表明SNF 6具有 与其他SNF/SWI组件不同的角色， 直接与基础转录因子结合。 拟议的工作将进一步 我们对发生在生物体之间的功能相互作用的理解 SNF/SWI复合物，转录因子和染色质组分在 启动子在其天然染色体中的转录激活 上下文

Transcriptional activation involves a complex interplay between gene- specific activators, the general transcription apparatus, and chromatin. In the yeast Saccharomyces cerevisiae, the SNF/SWI complex has an important role in this process and is required for transcriptional activation of diverse genes. The SNF/SWI complex facilitates activation by gene-specific regulatory proteins and has been implicated in remodeling chromatin to overcome chromatin-mediated repression. The complex comprises eleven proteins (including SWI1/ADR6, SNF2/SWI2, SWI3, SNF5, SNF6 and SNF11) and has been widely conserved in eukaryotes. Homologous proteins have been identified in Drosophila and mammals, and a similar complex has been purified from human. In the yeast system, genetic approaches can be applied to provide insight into physiologically important functions of the SVF/SWI complex. This proposal focuses on analysis of the interactions of the complex with other proteins in vivo. Three of the projects concern functional characterization of proteins identified in a previous two-hybrid screen for interaction with SNF2. First one of these interacting proteins, MSN1, is a candidate for an adaptor between gene specific transcriptional activators and the SNF/SWI complex. An intensive analysis of MSN1 will be carried out to test this model. Second, genes encoding the catalytic subunits of cAMP-dependent protein kinase were recovered in the two-hybrid screen, and the relationship of this kinase activity to the SNF/SWI complex will be assessed. Third, seven as yet unidentified interacting proteins will be characterized with the goal of obtaining new insights into SNF/SWI function. Finally, an analysis of the function and interactions of the SNF6 protein will be initiated. Genetics evidence suggests that SNF6 has a distinct role from other SNF/SWI components and perhaps interacts directly with basal transcription factors. The proposed work will further our understanding of the functional interactions that occur between the SNF/SWI complex, transcription factors, and chromatin components during transcriptional activation of promoters in their native chromosomal context.