SEARCH FOR SEC4P EFFECTORS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。在酿酒酵母中，从反式高尔基体到质膜的运输需要小的rabtype GTPase Sec4p。据认为，Sec4p被招募到反式高尔基体的分泌囊泡中，随后促进它们向质膜的运输。在那里，Sec4p似乎参与了外囊（一种膜系索复合物）的组装。然而，这个GTPase如何实现这些功能在很大程度上是不清楚的。gtp酶是所谓的分子开关，它在“开”（gtp绑定）和“关”（gdp绑定）状态之间循环。它们被认为是通过结合特定的、所谓的效应蛋白来实现其功能的。然而，到目前为止，我们只知道Sec4p的一种效应物，即Sec15p，它是质膜上囊胞复合物的一员。基于我们对Sec4p介导的分泌的广泛研究，该蛋白并不是Sec4p实现其功能的唯一效应器。因此，本研究的目的是鉴定Sec4p效应物并确定其作用。

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 transport from the trans-Golgi to the plasma membrane in Saccharomyces cerevisiae requires the small, Rab-type GTPase Sec4p. It is thought that Sec4p is recruited to secretory vesicles at the trans-Golgi and subsequently facilitates their transport to the plasma membrane. There, Sec4p appears to be involved in the assembly of the exocyst, a membrane tethering complex. However, how this GTPase achieves these functions is largely unclear. GTPases are so-called molecular switches, which cycle between an ¿¿on¿¿ (GTP-bound) and an ¿¿off¿¿ (GDP-bound) state. They are thought to accomplish their function by binding specific, so-called effector proteins in their ¿¿on¿¿ state. However, so far only one effector is known for Sec4p, which is Sec15p, a member of the exocyst complex at the plasma membrane. Based on our extensive studies of Sec4p-mediated secretion, this protein cannot be the only effector through which Sec4p achieves its functions. Therefore, the objective of this research is to identify Sec4p effectors and determine their role.