Activation and Regulation Mechanisms of cGMP-dependent Protein Kinase I and II

 描述(由申请人提供)：本提案的具体目的是获得cGMP依赖的蛋白激酶I和II(PKG)的cGMP结合域的高分辨率结构，并利用这些结构信息设计针对PKG的特异性激活剂。作为cGMP的关键受体，PKG I和II介导了cGMP升高药物的大部分作用，如用于治疗多种高血压疾病的一氧化氮释放药和用于治疗勃起功能障碍的磷酸二酯酶抑制剂。虽然PKG I和II是治疗高血压疾病的靶点，如动脉和肺动脉高压、心力衰竭、勃起功能障碍和骨质疏松症，但由于缺乏可用的结构信息，开发特定的激活剂一直是困难的。为了获得开发PKG I和II特异性激活剂所需的结构信息，本课题组最近确定了人PKG I和II调节结构域的一个片段的晶体结构，该片段与cGMP特异结合并激活催化活性。我的长期目标是了解cGMP介导的PKG的激活机制，并开发出可用于治疗高血压疾病的PKG特异性激活剂。为了实现这些目标，我的计划是了解非选择性A结构域在PKG I激活中的作用，了解PKG II的环核苷酸选择性机制，筛选已知的cGMP类似物的异构体特异性结合和激活，并确定它们的共晶结构，并利用得到的结构信息开发PKG I和II的异构体特异性激活剂。

 DESCRIPTION (provided by applicant): The specific aims of this proposal are to obtain high-resolution structures of the cGMP- binding domains of cGMP-dependent protein kinase I and II (PKGs) and to use the structural information to design activators specific for PKGs. As key receptors for cGMP, PKG I and II mediate most effects of cGMP-elevating drugs such as nitric oxide-releasing agents for the treatment of many hypertensive diseases and phosphodiesterase inhibitors for the treatment of erectile dysfunction. While PKG I and II are therapeutic targets fo treating hypertensive diseases such as arterial and pulmonary hypertension, heart failure, erectile dysfunction and osteoporosis, developing specific activators has been difficult mainly due to a lack of available structural information. To obtain structural information needed for developing specific activators of PKG I and II, our group recently determined crystal structures of a fragment of the regulatory domains of human PKG I and II that specifically bind cGMP and activate catalytic activity. My long-term goals are to understand the activation mechanism of PKG mediated by cGMP and to develop specific activators of PKG that can be used for treating hypertensive diseases. To achieve these goals, my plans are to understand the role of the non-selective A-domain in activation of PKG I, to understand the cyclic nucleotide selectivity mechanism of PKG II, to screen known cGMP analogs for isoform specific binding and activation, and determine their co-crystal structures and use the resulting structural information for developing isoform specific activators of PKG I and II.