PUI RESEARCH-MUW-BRANDON

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。 ICSA是一种自动运输的外膜蛋白，定位于志贺氏菌的旧极；在宿主结肠上皮细胞中，肌动蛋白细丝在同一极组装，用于细胞内游泳和细胞间扩散。有几条证据表明，ICSA在分泌前定位于细胞膜的内面，ICSA 必须先瞄准旧杆子，然后才能偷偷藏起来。今年夏天，我们在一次筛查中利用这些发现来确定ICSA的假定极地目标。我们还开发了一种筛查，以确定导致ICSA表达和分泌的因素，并确定ICSA和志贺氏菌中其他毒力蛋白的全球调节因子。 我们还对酵母中的四种蛋白质--Bud8p、Bud9p、Rax1p和Rax2p的靶向感兴趣，它们都参与了二倍体酵母细胞的两极萌发。Rax1p和Rax2p都靶向于二倍体细胞的两端，并且都参与了Bud8p和Bud9p对这些极点的靶向。有趣的是，Rax蛋白分别针对远端和近端的Bud8p和Bud9p(相对于最近的芽)。Rax1p和/或Rax2p的缺失导致芽蛋白的异常靶向，从而使出芽的轴向分布 观察到的，与芽的振荡两极分布相反 野生型二倍体细胞的特征。我们感兴趣的是 Rax1p/Rax2p复合体靶向的分子机制以及这些蛋白在Bud8p和Bud9p的差异靶向中所起的作用。 我们已经使用了聚合酶链式反应和体内重组来干扰Rax1和Rax2基因，这些突变将在合成基因组阵列中进行分析。

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. IcsA, an autotransported outer membrane protein is targeted to the old pole of the Shigella; the same pole where actin filaments are assembled for intracellular swimming and intercellular dissemination in host colonic epithelial cells. Several lines of evidence suggests that IcsA is targeted to the inner face of the cytoplasmic membrane before secretion and that IcsA must be targeted to the old pole before it is secreted. During the summer we have exploited these findings in a screen to identify a putative polar target for IcsA. We have also developed a screen to identify factors that are responsible for the expression and secretion of IcsA and to identify global regulators of IcsA and other virulence proteins in Shigella. We are also interested in the targeting of four proteins in yeast--Bud8p, Bud9p, Rax1p and Rax2p that are all involved in bipolar budding in diploid yeast cells. Rax1p and Rax2p are both targeted to both ends of diploid cells and are both involved in the targeting of Bud8p and Bud9p to these poles. Interestingly, the Rax proteins target Bud8p and Bud9p to the distal and proximal poles (with respect to the most recent bud), respectively. Deletions in Rax1p and/ or Rax2p lead to aberrant targeting of the Bud proteins such that an axial distribution of budding is observed as opposed to the oscillating bipolar distribution of buds characteristic of wild type diploid cells. We are interested in the molecular mechanism for targeting of the Rax1p/Rax2p complex and the role that these proteins play in the differential targeting of Bud8p and Bud9p. We have used pcr in concert with in vivo recombination to disrupt the Rax1 and Rax2 genes these mutations will be analyzed in a Synthetic Genomic Array screen.