DOXORUBICIN TRANSPORT ATPase: MODEL FOR DRUG RESISTANCE

描述：（由申请人提供）该项目将研究 ABC 型转运 ATP 酶 DrrAB，它赋予阿霉素和 生产生物链霉菌中的柔红霉素。 DrrAB 组成 两个亚基 DrrA 和 DrrB。有趣的是，DrrA 与 P-糖蛋白，一种多药耐药蛋白，以及 ABC 的其他成员 系列包括 CFTR 和 ABC 1。 DrrAB 和 Pgp 在功能上也相似： 两者都赋予多柔比星抗性，生产者生物体中的 DrrAB 和生产者生物体中的 Pgp 癌细胞。由于序列、结构和功能相似 DrrAB 和 Pgp 之间，很可能它们有一个共同的祖先。因此， 阐明“Drr”的功能和药物结合位点的性质 “Drr”中的内容将阐明 Pgp 的功能机制以及 多重耐药性的演变。此外，DrrAB 非常适合 了解膜域和催化域之间的相互作用 ABC 运输机。初步实验表明 DrrA 和 DrrB 生化耦合； DrrA 是稳定和维护所必需的 膜中的 DrrB 和 DrrB 是 DrrA 活性所必需的。实验 将被设计来检验 DrrA 与 DrrB 形成复合物的假设，并且 在 DrrB 靶向膜之前保护其免受蛋白水解， 研究两个亚基之间相互作用的实验将包括 生化和遗传学方法，包括相互作用缺陷的分离 突变体和第二位点抑制子。这些研究将具有相关性 了解膜蛋白的靶向并阐明其作用 通过催化结构域稳定多结构域的膜结构域或 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.