Yeast yapsins and cell wall assembly

我们的实验室感兴趣的是一个独特的真菌酶家族的调节和功能作用，统称为“雅蛋白酶”，在酵母细胞壁的组装。这种结构是高度复杂的，对于所有真菌的生存能力是必不可少的，包括人类机会主义病原体，如C。白色念珠菌这个家族的第一个成员是Yps 1酶，我们和其他人在啤酒酵母S.十年前的酿酒厂我们现在知道这些酶的五个成员在S.在酿酒酵母中，它们都位于细胞表面。最近的研究表明，这些酶与细胞壁组装的某些方面有关，但直到最近，还没有发现这些酶的底物。我们最近在S.酿酒酵母和这些底物的性质清楚地证实了Yps 1参与细胞壁组装。我们最近的研究还表明：1）在它们到达细胞表面的细胞内运输过程中，这些酶与大多数其他注定要分泌的蛋白质保持分离; 2）环境pH调节这种酶的活性。在目前的建议中，我们设计了实验：1）确定额外的Yps 1底物; 2）确认和理解这种酶正在进行的特定细胞内转运的意义; 3）理解是什么控制了这种酶的活性。除了加深我们对真菌yapsins如何调节酵母细胞壁组装的理解外，拟议的研究还将有助于设计可能导致新型抗真菌药物开发的特异性抑制剂。

Our laboratory is interested in the regulation and functional role of a unique family of fungal enzymes, collectively known as 'yapsins', in the assembly of the yeast cell wall. This structure is highly complex and essential for the viability of all fungi, including human opportunist pathogens such as C. albicans. The first member of this family is the Yps1 enzyme that we, and others, identified in the brewer yeast S. cerevisiae a decade ago. We now know that five members of theses enzymes are expressed in S. cerevisiae, all of them are localized at the cell surface. Recent studies suggested that these enzymes were implicated in some aspects of cell wall assembly, but until recently, no substrate for any of these enzymes had been identified. We recently identified some natural substrates for Yps1 in S. cerevisiae and the nature of these substrates clearly confirmed that Yps1 participate in the cell wall assembly. Our recent study also suggested that: 1) during their intracellular transport to reach the cell surface, these enzymes are kept apart from most other proteins destined for secretion; and 2) the environmental pH regulates the activity of this enzyme. In the current proposal we have designed experiments to: 1) identify additional Yps1 substrates; 2) confirm and understand the significance of the particular intracellular transport that this enzyme is taking; and 3) understand what controls the activity of this enzyme. In addition to deepen our understanding on how fungal yapsins regulate cell wall assembly in yeast, the proposed studies should help designing specific inhibitors that may lead to the development of novel antifungal agents.