The Arrest of Secretion Response

最近对酵母“分泌抑制反应”（ASR）的观察记录了细胞内信号的一种新形式：启动信号的蛋白质，尽管通常位于细胞表面，但必须被困在细胞内隔室中才能发出信号。该项目将探索沿着这一信号通路运作的分子机制。在ASR中，抑制sec突变体沿分泌路径的运输使核孔复合物（NPC）的蛋白质重新定位，抑制核输入，并将核质蛋白重新定位到细胞质中。这些事件需要蛋白激酶C （Pkc1p）和Wsc家族的两个跨膜蛋白。然而，它们不需要Pkc1p MAP激酶级联。此外，与那些通常在质膜上的蛋白相反，Wsc蛋白被困在分泌路径上是信号传递所必需的。因此，这项工作将确定Pkc1p是否与Wsc蛋白相关，以及这种关联是否取决于是否发生活跃的ASR， *分泌途径被抑制时是否产生二酰基甘油，即在ASR期间，*遗传筛选是否可以识别所需的信号中间体，特别是那些在Pkc1p下游起作用的中间体。

Recent observations on the "arrest of secretion response" (ASR) in yeast have documented a novel form of intracellular signaling: the protein which initiates the signal, although it is normally at the cell surface, must be trapped within intracellular compartments in order to signal. This project will explore molecular mechanisms which operate along this signaling pathway. In the ASR, inhibition of transport along the secretory path in sec mutants relocates proteins of the nuclear pore complex (NPC), inhibits nuclear import and also relocates nucleoplasmic proteins to the cytoplasm. Protein kinase C (Pkc1p) and two of the transmembrane proteins of the Wsc family are required for these events. They nevertheless do not require the Pkc1p MAP kinase cascade. Moreover, Wsc proteins trapped along the secretory path are required for signaling, as opposed to those which are normally at the plasma membrane. Thus, this work will determine * Whether Pkc1p associates with Wsc proteins and whether such association depends on whether an active ASR is occurring, * Whether diacylglycerol is generated when the secretory path is inhibited, i.e. during the ASR, * Whether a genetic screen can identify signaling intermediates which are required, especially those which function downstream of Pkc1p.