REGULATION OF GLYCEROPHOSPHOINOSITOL TRANSPORT IN YEAST

描述(申请人摘要)：磷脂酶介导的脱乙酰基 磷脂酰肌醇(P1)产生胞外甘油磷酸肌醇 (GroPIns)是酿酒酵母细胞的主要分解代谢途径。 含肌醇的培养液。在肌醇受限的时候，GroPlns是 在需要能量的过程中被输送回细胞内，由 GIT1基因的产物。这种新型的膜渗透酶具有许多 有趣的特点，使其值得深入研究。吉蒂普是第一个 GroPlns转运蛋白是任何生物体的特征，有证据表明 高等真核生物中存在这样的转运蛋白。格罗普恩夫妇 通过Gitlp输送用于合成PT及其 含有肌醇的衍生物，其中许多在信号中起着重要的作用 转导。因此，GITIP的活动可能会影响到一些 重要的细胞事件。此外，有证据表明交通工具 GroPlns通过GITIP的表达受到磷脂代谢和GITIP的调节 磷酸盐代谢增加了表征调控的前景 连接细胞新陈代谢的这两个基本方面的网络 对吉蒂普的研究。最后，GIT1的独特染色体定位 为研究转录沉默在细胞内的作用提供了机会。 调节GIT1的表达。这项提案的具体目的是审查 GroPlns在转录和转录水平对GITIP转运的调控 翻译后水平：1)磷脂代谢，2)未折叠蛋白质 反应途径，3)磷酸盐代谢，4)基因定位。

DESCRIPTION (Applicant's abstract): The phospholipase-mediated deacylation of phosphatidylinositol (P1) to produce extracellular glycerophosphoinositol (GroPIns) is a major catabolic pathway in S. cerevisiae cells grown in inositolcontaining medium. In times of inositol limitation, GroPlns is transported back into the cell in an energy requiring process mediated by the product of the GIT1 gene. This novel membrane permease has a number of interesting features that make it worthy of intensive study. Gitip is the first GroPlns transporter to be characterized in any organism, and there is evidence for the existence of such a transporter in higher eukaryotes. The GroPlns transported through Gitlp is used for the synthesis of PT and its inositol-containing derivatives, many of which play important roles in signal transduction. Thus, the activity of Gitip may impinge upon a number of important cellular events. In addition, evidence suggesting that the transport of GroPlns through Gitip is regulated by both phospholipid metabolism and phosphate metabolism raises the prospect of characterizing the regulatory networks linking these two fundamental aspects of cellular metabolism by means of the study of Gitip. Finally, the unique chromosomal location of GIT1 provides an opportunity to study the role of transcriptional silencing in regulating GIT1 expression. The Specific Aims of this proposal are to examine the regulation of GroPlns transport through Gitip at the transcriptional and posttranslational levels by 1) phospholipid metabolism, 2) the Unfolded Protein Response Pathway, 3) phosphate metabolism ,and 4) gene location.