RECEPTOR AND TRANSPORTER REGULATION OF NO SYNTHASES

内皮型和诱导型一氧化氮合酶（eNOS和iNOS）在正常血管生理学和血管病理学中具有关键的调节作用。 在这个建议中提出的初步研究表明，eNOS直接与缓激肽B2受体和CAT 1阳离子氨基酸转运蛋白在血管内皮细胞中相互作用。 此外，它已被证明，诱导型一氧化氮合酶与CAT 2阳离子氨基酸转运蛋白在血管平滑肌细胞共诱导。 由于iNOS和CAT 2在结构和功能上与eNOS和CAT 1非常相似，我们假设iNOS和CAT 2也在平滑肌中相互作用。 在本申请中，我们提出测试eNOS在内皮细胞中通过与B2受体的抑制性相互作用来调节的假设。 我们还将确定酪氨酸磷酸化在调节相互作用中的作用，并确定负责相互作用的两种蛋白质中的结构域。 我们进一步提出测试的假设，eNOS-CAT 1相互作用促进NO从内皮细胞的释放，并将确定在两种蛋白质的相互作用域。 最后，我们将检验iNOS-CAT 2相互作用促进血管平滑肌细胞NO释放的假设，并将定义参与相互作用的两种蛋白质中的结构域。

The endothelial and inducible nitric oxide synthases (eNOS and iNOS) have key regulatory roles in both normal vascular physiology and in vascular pathology. Preliminary studies presented in this proposal indicate that eNOS interacts directly with the bradykinin B2 receptor and with the CAT1 cationic amino acid transporter in vascular endothelial cells. In addition, it has been shown that iNOS is coinduced with the CAT2 cationic amino acid transporter in vascular smooth muscle cells. Because iNOS and CAT2 are structurally and functionally very similar to eNOS and CAT1, we postulate that iNOS and CAT2 also interact in smooth muscle. In this application, we propose to test the hypothesis that eNOS is regulated in endothelial cells by inhibitory interactions with the B2 receptor. We will also determine the role of tyrosine phosphorylation in regulation of the interaction and will define the domains in the two proteins that are responsible for the interaction. We further propose to test the hypothesis that the eNOS-CAT1 interaction facilitates NO release from endothelial cells and will determine what the interacting domains are in the two proteins. Finally, we will test the hypothesis that the iNOS-CAT2 interaction facilitates NO release from vascular smooth muscle cells and will define the domains in the two proteins that are involved in the interaction.