Cardiac myosin light chain 1 dependent regulatory mechanisms in dilated cardiomyopathy

肌凝蛋白基本轻链（cMLC-1）作为肌节的一部分与运动肌凝蛋白密切相互作用。如申请人所示，cMLC-1可以在两个高度保守的磷酸化位点Thr64和Ser195磷酸化。在遗传斑马鱼模型中，Ser195磷酸化位点的缺乏导致心脏收缩性严重受损，暗示其在肌节功能中起关键作用。然而，cMLC-1在扩张型心肌病或心力衰竭中的作用和精确调控尚不清楚。该研究旨在揭示cMLC-1翻译后磷酸化的功能相关性和相关的调控途径，并剖析其对人类心脏病的贡献。我们的目标是在体外鉴定和验证cMLC-1相互作用伙伴，特别关注负责其翻译后修饰的激酶和磷酸酶。关于直接相互作用伙伴的知识将用于定义潜在的调节途径以及激活和抑制模式，这是潜在治疗翻译的序曲。下一步，研究人员将在体内研究cMLC-1调节改变的功能后果。我们将在工程转基因斑马鱼模型中探讨cMLC-1基因改变和翻译后修饰的生物学意义，以及确定的心脏功能相互作用伙伴。阐明cMLC-1的分子特性将有助于加深我们对肌节功能的基本认识，并确定心肌病和心力衰竭分子治疗策略的靶点。

The essential myosin light chain (cMLC-1) as part of the sarcomere is closely interacting with motor-myosin. As shown by the applicant, cMLC-1 can be phosphorylated at two highly conserved phosphorylation sites, Thr64 and Ser195. Lack of the phosphorylation site at Ser195 causes severely impaired cardiac contractility in a genetic zebrafish model, hinting at a pivotal role in sarcomere function. However, the contribution and precise regulation of cMLC-1 in dilated cardiomyopathy or heart failure is unknown.The proposed research aims to unravel the functional relevance of cMLC-1 posttranslational phosphorylation and the associated regulatory pathways and dissect its contribution to human heart disease. We aim to identify and validate cMLC-1 interaction partners in vitro with special focus on kinases and phosphatases responsible for its posttranslational modification. The knowledge about direct interaction partners will be used to define underlying regulatory pathways as well as modes of activation and inhibition, a preamble for potential therapeutic translation. In a next step towards therapeutic modulation, the functional consequence of altered cMLC-1 regulation is investigated in vivo. We will explore the biological significance of genetic alterations and posttranslational modifications of cMLC-1 as well as the identified interaction partners on heart function in engineered transgenic zebrafish models. Elucidating the molecular properties of cMLC-1 will help to deepen our basic understanding of sarcomere function and define targets for molecular treatment strategies of cardiomyopathy and heart failure.