Junctophilin-2 cleavage in ischemic heart disease

项目概要/摘要 缺血性心脏病是美国的主要死因。在细胞水平，心肌 局部缺血改变了兴奋-收缩偶联并促进心力衰竭的发展。嗜连接蛋白-2 （JPH 2）是维持质膜和肌浆网（SR）的膜间连接蛋白。 以促进兴奋-收缩偶联。缺血/再灌注损伤与缺血性心脏 疾病导致JPH 2蛋白水平的损失，这部分是由Ca 2+敏感的蛋白水解引起的。 钙蛋白酶我们这个项目的长期目标是阐明分子和细胞机制， 哪种钙蛋白酶引起JPH 2裂解以及随之而来的JPH 2 C-末端肽如何改变心肌功能。 我们将测试中心假设，即钙蛋白酶切割JPH 2释放C末端肽， 心肌细胞核，在那里它改变影响心肌重塑的CaMKII-d剪接。

PROJECT SUMMARY / ABSTRACT Ischemic heart disease is a major cause of death in the United States. At the cellular level, myocardial ischemia alters excitation-contraction coupling and promoted the development of heart failure. Junctophilin-2 (JPH2) is an inter-membrane linker protein that maintains the plasmalemma and sarcoplasmic reticulum (SR) at a fixed distance to facilitate excitation-contraction coupling. Ischemia/reperfusion injury and ischemic heart disease lead to a loss of JPH2 protein levels, which in part is caused by proteolysis by the Ca2+-sensitive enzyme calpain. Our long-term goal of this project is to elucidate the molecular and cellular mechanisms by which calpain causes JPH2 cleavage and how the ensuing JPH2 C-terminal peptide alters myocardial function. We will test the central hypothesis that calpain cleaves JPH2 to release a C-terminal peptide that traffics into the cardiomyocyte nucleus where it alters CaMKII-d splicing which affects myocardial remodeling.