DOXORUBICIN TRANSPORT ATPase: MODEL FOR DRUG RESISTANCE

描述：(申请人提供)这个项目将研究一种ABC类型的转运蛋白ATPase，DrrAB，它对阿霉素和 柔红霉素在生产者有机体白链霉菌中。DrrAB包括 DrrA和DrrB两个亚基。有趣的是，DrrA与 P-糖蛋白，一种多药耐药蛋白，对ABC的其他成员 包括CFTR和ABC 1的家族。DrrAB和Pgp在功能上也相似： 两者都与阿霉素耐药有关，产生菌中的DrrAB和Pgp 癌细胞。由于序列、结构和功能的相似性 在DrrAB和Pgp之间，它们可能有共同的祖先。因此， 阐明‘DRR’的功能和药物结合部位的性质 将有助于阐明PGP的作用机制和PGP的 多药耐药的演变。此外，DrrAB非常适合于 理解膜结构域和催化结构域之间的相互作用 美国广播公司的运输商。初步实验表明，DrrA和DrrB是 生物化学偶联；DRRA是稳定和维持 膜中的DrrB和DrrB是DrrA活性所必需的。实验 将被设计用来检验这样的假设，即DrrA与DrrB形成络合物 在DrrB被定位到膜上之前保护它不被蛋白质降解， 研究两个亚基之间相互作用的实验将由两个亚基组成 生化和遗传方法，包括分离相互作用缺陷 突变体和第二位点抑制子。这些研究将在 了解膜蛋白的靶向性及其在阐明其作用中的作用 通过催化结构域稳定多结构域或多结构域 多亚基蛋白质。

DESCRIPTION: (provided by applicant) This project will investigate an ABC-type of transport ATPase, DrrAB, that confers resistance to doxorubicin and daunorubicin in the producer organism Streptomyces peucetius. DrrAB consists of two subunits DrrA and DrrB. Interestingly, DrrA bears homology to P-glycoprotein, a multidrug resistance protein, and to other members of the ABC family including CFTR and ABC 1. DrrAB and Pgp are also functionally similar: both confer doxorubicin resistance, DrrAB in the producer organism and Pgp in cancer cells. Because of the sequence, structural and functional similarity between DrrAB and Pgp, it is likely that they share a common ancestor. Hence, elucidation of the function of 'Drr' and the nature of the drug binding sites in 'Drr' will shed light on the mechanism of function of Pgp and on the evolution of multidrug resistance. Furthermore, DrrAB is ideal for understanding interaction between the membrane domain and the catalytic domain of ABC transporters. Preliminary experiments have shown that DrrA and DrrB are biochemically coupled; DrrA is required for the stability and maintenance of DrrB in the membrane and DrrB is required for the activity of DrrA. Experiments will be designed to test the hypothesis that DrrA forms a complex with DrrB and protects it from proteolysis before DrrB is targeted to the membrane, Experiments to study interaction between the two subunits will consist of both biochemical and genetic approaches including isolation of interaction-defective mutants and the second-site suppressors. These studies will have relevance in understanding targeting of membrane proteins and in elucidating the role played by the catalytic domains in stabilizing the membrane domains of multidomain or multisubunit proteins.