FUNCTIONAL STUDIES OF CALRETICULIN AND RO/SS A COMPLEX

Ro/SS-A自身抗原是一种复杂的核糖核蛋白。 针对这种复合物的自身抗体是 常见于红斑狼疮和干燥综合征患者 s综合征。 一些参与这个复合物的分子是 已知的包括52 kDa蛋白（Ro 52）、60 kDa蛋白（Ro 60)dhYRNA。 最近，在体外和体内研究中， 我们的实验室进一步提出第三种蛋白质，钙网蛋白 (CR)，长期以来一直被怀疑是 事实上，Ro/SS-A复合物确实与hYRNA和52 kD的 Ro多肽。 然而，分子间的相互作用 Ro/SS-A颗粒内的蛋白质和蛋白质-RNA仍然是 不太了解。 利用重组蛋白系统地 研究这种粒子中蛋白质之间的相互作用可以帮助 我们可以更好地理解这种复合物在分子水平上的形成， 水平 酵母双杂交分析以及体外蛋白质-蛋白质 将进行相互作用研究，以检查这种相互作用 在这些蛋白质中。 相互作用蛋白质的结构域将是 详细解剖，以确定蛋白质基序负责 联系人. 寻找其他蛋白质伴侣， 通过筛选酵母的方法， 双杂交文库揭示了Ro 52和 IgG的Fc区。 对这种相互作用的详细审查 将在体外试验和哺乳动物中进一步研究 系统

The Ro/SS-A autoantigen is a complex ribonucleoprotein. Autoantibodies against the components of this complex are frequently found in patients with lupus erythematosus and S jogren s syndrome. Some molecules involved in this complex are known, including a 52 kDa protein (Ro 52), a 60 kDa protein (Ro 60) an dhYRNAs. Recently, both in vitro and in vivo studies in our lab have further suggested that a third protein, calreticulin (CR), which has long been suspected to be a component of the Ro/SS-A complex does, in fact, bind to hYRNA and the 52 kD Ro polypeptide. However, the molecular interactions between proteins and proteins-RNAs within the Ro/SS-A particle are still poorly understood. Using recombinant proteins to systematically study proteins-protein interactions within this particle could help us better understand the formation of this complex at a molecular level. Yeast two-hybrid analysis as well as in vitro protein-protein interaction studies will be performed to examine such interactions among these proteins. The domains of interacting proteins will be dissected in detail to identify the protein motifs responsible for the contacts. Searching other protein partners which will interact with constituents of this complex by the approach of screening a yeast two-hybrid library has revealed an interaction between Ro 52 and the Fc region of IgG. Detailed examination of such interaction will be further studied in an in vitro assay and in a mammalian system.