Regulation of guanylyl cyclase

描述（由申请人提供）：可溶性胍基环化酶（sGC）是NO-cyclic GMP （cGMP）信号级联中的关键酶之一，参与平滑肌松弛、抑制血小板聚集和神经传递。sGC是目前用于治疗心血管疾病的各种药理化合物的靶点。然而，调控sGC活性或表达的机制尚不清楚。为了治疗目的而有效地操纵sGC依赖的cGMP合成需要了解sGC水平和活性调节所涉及的途径。本课题的目标是确定由变松效应物激活酶的分子机制，包括发展no独立调控sGC的方法，研究sGC表达的调控机制，分析短期和长期调控sGC活性和表达对细胞生理的影响。为了实现这一目标，一个组成型激活的sGC突变体将在一个cGMP水平升高的细胞模型中表达，而参与sGC功能异二聚体形成的结构域的表达将导致酶水平降低，降低no依赖性cGMP的合成。鉴定和表征sGC基因的启动子片段，建立sGC转录后调控机制，建立人类细胞培养模型，确定sGC短期和长期调控对细胞生理的影响。了解sGC调控机制将有助于我们进一步了解sGC/cGMP系统在各种生物过程中的作用。

DESCRIPTION (provided by applicant): Soluble guanylyl cyclase (sGC) is one of the crucial enzymes in the NO-cyclic GMP (cGMP) signaling cascade involved in smooth muscle relaxation, inhibition of platelet aggregation, and neurotransmission. sGC is the target of various pharmacological compounds currently used for treatment of cardiovascular disorders. However, the mechanisms governing stimulation of activity or expression of sGC are poorly understood. Effective manipulation of sGC-dependent synthesis of cGMP for therapeutic purposes requires understanding of the pathways involved in regulation of sGC levels and activity. The goal of this proposal is to determine the molecular mechanism of enzyme activation by alisoteric effectors including development of approaches for NO-independent regulation of sGC, investigation of the mechanisms regulating sGC expression, and analysis of the effects of short-term and long-term modulation of sGC activity and expression on cell physiology. To achieve this goal, a constitutively activated sGC mutant will be expressed in a cell model providing for elevated levels of cGMP, whereas expression of domains involved in formation of functional heterodimers of sGC will result in decreased enzyme levels and lowered NO-dependent synthesis of cGMP. The promoter fragments of sGC genes will be identified and characterized as well as the mechanisms of post-transcriptional regulation of sGC Human cell culture models will be developed and the effects of short-term and long-term sGC regulation on cell physiology will be determined. The knowledge of the mechanism of sGC regulation will advance our understanding of the role of sGC/cGMP system in various biological processes.