Strukturelle Basis der Polyadenylierung zytoplasmatischer Boten-RNA durch den GLD-2/GLD-3 Proteinkomplex

信使RNA的多聚腺苷酸化是真核生物的一个重要过程。在细胞核中，它影响mRNA的稳定性和转运，而在细胞质中，它影响mRNA的翻译效率。胞质多聚腺苷酸化对于多种细胞过程是必需的。例如，在卵母细胞成熟和早期发育过程中的特定时间，通过添加poly（A）尾，母体来源的dorsalic胞质mRNA被激活用于蛋白质合成。多聚腺苷酸化是由多聚腺苷酸聚合酶（PAP）进行的，多聚腺苷酸聚合酶是核苷酸转移酶家族的蛋白质，其催化核心结构域在物种间高度保守。与核PAP相反，细胞质PAP被其他蛋白质激活并与其他蛋白质联合作用。其功能的结构基础目前尚不清楚。我计划表征细胞质poly（A）聚合酶GLD-2/GLD-3复合物的X射线结构。这种复杂的多聚腺苷酸化一组生殖系秀丽隐杆线虫进入减数分裂的mRNA。我将使用结构信息来了解GLD-2/GLD-3如何识别其底物mRNA，以及它如何与典型的poly（A）聚合酶大家族不同。结构分析将允许在体外解剖GLD-2/GLD-3功能，并合作研究其体内特性和动力学。

Polyadenylation of messenger RNA is an essential process in eukaryotes. In the nucleus it influences mRNA stability and transport, while in the cytoplasm it impacts on mRNA translational efficiency. Cytoplasmic polyadenylation is essential for a variety of cellular processes. Dormant cytoplasmic mRNAs of maternal origin, for example, are activated for protein synthesis at specific times during oocyte maturation and early development by addition of a poly(A) tail. Polyadenylation is carried out by poly(A) polymerases (PAPs), proteins of the nucleotidyl-transferase family whose catalytic core domain is highly conserved across species. In contrast to nuclear PAPs, cytoplasmic PAPs are activated by and act in conjunction with other proteins. The structural basis for their function is currently unknown. I plan to characterize the X-ray structure of the cytoplasmic poly(A) polymerase GLD-2/GLD-3 complex. This complex polyadenylates a set of germline C.elegans mRNAs at the entry into meiosis. I will use the structural information to understand how GLD-2/GLD-3 recognizes its substrate mRNAs and how it has diverged from the large family of canonical poly(A) polymerases. The structural analysis will allow dissecting GLD-2/GLD-3 function in vitro, and, in collaboration, to study its properties and dynamics in vivo.