MOLECULAR MECHANISM OF ADENYLYL CYCLASE SUPERACTIVATION

腺苷酸环化酶超激活的分子机制

• 批准号: 6838749
• 负责人: HENRY I YAMAMURA
• 金额: $ 26.66万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6838749
• 关键词: MOLECULAR; MECHANISM; ADENYLYL; CYCLASE; SUPERACTIVATION

EXCEED THE SPACE PROVIDED. Analgesics that act through the 5 opioid receptor have low addictive potential but similarly to classical opiates, display tolerance after long-term treatment. Chronic opioid receptor stimulation leads to a compensatory increase in adenylyl cyclase (AC) activity, called AC superactivation. We have demonstrated that an AC isoenzyme (AC VI) is phosphorylated upon chronic 5opioid agonist (SNC 80) treatment in CHO cells transfected with the human 8 opioid receptor (hDOPJCHO). We hypothesize that phosphorylation of AC VI is involved in adenylyl cyclase superactivation, and that superactivation is involved in tolerance to chronic 8 opioid agonists. In preliminary experiments we found that o_-transducin, a putative scavenger of G protein 133,- subunits, attenuated both chronic SNC 80 mediated phosphorylation of AC VI and AC superactivation. In this proposal we will use other, independent methods, to study the involvement of G protein 133,-subunitsin cellular responses to acute- and chronic SNC 80 treatment. Attenuation of AC superactivation and AC VI phosphorylation by these methods will confirm the role of G protein 133,-subunitsin chronic SNC 80-mediated respolises. Subsequently we will show that free 133,-subunitsr,eleased upon chronic SNC 80 treatment, regulate the activity of second messenger regulated protein kinases and Raf-1 protein kinase in hDOR/CHO cells. Finally, we will demonstrate that depletion of the protein kinase responsible for phosphorylation of AC VI in hDOR/CHO cells also attenuates chronic 8 opioid agonist mediated AC superactivation. Better understanding of the molecular mechanisms of drug tolerance at the human 5 opioid receptor should aid in the development of longer acting analgesics with fewer side effects. PERFORMANCE SITE ========================================Section End===========================================

超出所提供的空间。通过 5 阿片受体发挥作用的镇痛药具有较低的成瘾性，但与经典阿片类药物类似，长期治疗后会表现出耐受性。慢性阿片受体刺激会导致腺苷酸环化酶 (AC) 活性代偿性增加，称为 AC 超激活。我们已经证明，在用人 8 阿片受体 (hDOPJCHO) 转染的 CHO 细胞中，长期使用 5 阿片激动剂 (SNC 80) 治疗时，AC 同工酶 (AC VI) 会被磷酸化。我们假设 AC VI 的磷酸化与腺苷酸环化酶的超活化有关，并且该超活化与对慢性 8 阿片类激动剂的耐受有关。在初步实验中，我们发现o_-转导蛋白（G 蛋白 133,- 亚基的假定清除剂）减弱了慢性 SNC 80 介导的 AC VI 磷酸化和 AC 超激活。在本提案中，我们将使用其他独立的方法来研究 G 蛋白 133,-亚基在急性和慢性 SNC 80 治疗的细胞反应中的参与情况。通过这些方法减弱 AC 超活化和 AC VI 磷酸化将证实 G 蛋白 133,-亚基在慢性 SNC 80 介导的反应中的作用。随后我们将证明，长期 SNC 80 处理后释放的游离 133,-亚基可调节 hDOR/CHO 细胞中第二信使调节的蛋白激酶和 Raf-1 蛋白激酶的活性。最后，我们将证明 hDOR/CHO 细胞中负责 AC VI 磷酸化的蛋白激酶的消耗也会减弱慢性 8 阿片受体激动剂介导的 AC 超激活。更好地了解人类 5 阿片受体药物耐受的分子机制应有助于开发具有更少副作用的长效镇痛药。表演网站==========================================部分结束====== =======================================