Regulation of cell polarity by interactors of the PAK-family kinase Ste20 in budding yeast

小的GTdCdc42在细胞极性中起着关键作用。在芽殖酵母Saccharomyces cerevisiae中，在营养生长期间以及在交配和丝状生长期间，在细胞周期的不同阶段需要它。PAK家族激酶Ste20是Cdc42的下游效应子之一。由于只有少数基板的Ste20已被描述，我们最近进行了筛选，以确定新的相互作用的Ste20。该项目的目的是这些相互作用的特点。使用酵母遗传学以及生物化学方法，如免疫共沉淀和亲和纯化，我们将检查是否相互作用是生理相关的。此外，将测试蛋白质是否以Ste20依赖性方式磷酸化。根据蛋白质，将进行功能测定（例如肌动蛋白成核），以更好地了解潜在的分子机制。

The small GTPase Cdc42 plays a key role in cell polarity. In the budding yeast Saccharomyces cerevisiae it is required at different stages of the cell cycle during vegetative growth but also during mating and filamentous growth. The PAK-family kinase Ste20 is one of the downstream effectors of Cdc42. Since only few substrates for Ste20 have been described, we recently carried out a screen in order to identify novel interactors of Ste20. The aim of this project is the characterization of these interactions. Using yeast genetics as well as biochemical approaches such as co-immunoprecipitations and affinity purifications we will examine whether the interactions are physiologically relevant. Further, it will be tested whether the proteins are phosphorylated in a Ste20-dependent manner. Depending on the protein, functional assays (e.g. actin nucleation) will be carried out to gain a better understanding of the underlying molecular mechanisms.