SEARCH FOR SEC4P EFFECTORS

点击翻译按钮获取中文摘要

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.