CaMKII activation and regulation in adult cardiac myocytes

项目总结/摘要 钙调素依赖性蛋白激酶（CaMKII）是心脏功能的重要调节因子， 在病理状态下，调节离子通道、钙转运体、肌丝 和核转录。CaMKII通常可以微调这些过程。但在病理学上， 如心力衰竭（HF）等疾病，慢性自主CaMKII激活可过度磷酸化 靶点，由于对几种离子通道和Ca- 处理蛋白质慢性CaMKII激活也是几种病理状态的标志 急性或遗传性CaMKII抑制可减少心律失常和HF的进展。因此 理解心肌细胞中CaMKII调节的基本方面是至关重要的 了解功能障碍和潜在的治疗方法。我们和其他人发现了几个新的 翻译后修饰（PTM）可以将CaMKII捕获在激活状态，而不是 在局部钙瞬变的情况下快速开启和关闭。自磷酸化、氧化、GlcNAc酰化 和S-亚硝基化在CaMKII上的调节热点内产生记忆和自主 活性，即使当Ca/CaM福尔斯下降。在其他位点也有3个PTM抑制CaMKII activation.目标1和2将直接测量这些PTM如何差异性地影响激活， 在成人心肌细胞中的CaMKII的记忆，以填补在这一领域的主要知识空白。目标3 将测试CaMKII的S-亚硝基化是否需要在一个单一的网站，为心脏的内在 对急性和慢性压力反应的钙瞬变和收缩增加的反应 超负荷（或Anrep效应）。CaMKII在射血减少的HF中具有公认的作用 （HFrEF），但其在保留射血功能的HF（HFpEF）中的作用尚不清楚。目标4将直接测试 CaMKII在两个新的HFpEF模型中的参与。拟议的研究将产生重大影响 我们对CaMKII活性如何在心脏中调节的理解， 病理学，可能是治疗干预的目标。

Project Summary/ Abstract Ca-Calmodulin dependent protein kinase (CaMKII) is an important regulator of cardiac function, and dysfunction in pathological states, regulating ion channels, Ca transporters, myofilaments and nuclear transcription. CaMKII may normally fine-tune these processes. But in pathological conditions like heart failure (HF), chronic autonomous CaMKII activation can over-phosphorylate targets, contributing to arrhythmogenesis due to acute effects on several ion channels and Ca- handling proteins. Chronic CaMKII activation is also a hallmark of several pathological states and acute or genetic CaMKII inhibition can reduce arrhythmias and the progression of HF. Thus understanding fundamental aspects of CaMKII regulation in cardiac myocytes is critical understanding dysfunction and potential therapeutics. We and others discovered several novel post-translational modifications (PTMs) that can trap CaMKII in an activated state, rather than turning on & off rapidly with local Ca transients. Autophosphorylation, oxidation, GlcNAcylation and S-nitrosylation within a regulatory hotspot on CaMKII creates memory and autonomous activity, even when Ca/CaM falls. There are also 3 PTMs at other sites that suppress CaMKII activation. Aims 1 and 2 will directly measure how these PTMs differentially affect activation and memory of CaMKII in adult cardiac myocytes, to fill a major knowledge gap in this field. Aim 3 will test whether CaMKII S-nitrosylation at a single site is required for the heart’s intrinsic response to increase Ca transients and contraction in response to acute and chronic pressure overload (or the Anrep effect). CaMKII has well-recognized roles in HF with reduced ejection (HFrEF), but its role in HF with preserved ejection (HFpEF) is unclear. Aim 4 will directly test the engagement of CaMKII in two new HFpEF models. The proposed studies will have major impact on our understanding of how CaMKII activity is regulated in heart, in ways that promote pathology and might be targets for therapeutic intervention.