Structure Changes of Ion-motive ATPases

描述(申请人提供)：建议的研究重点是SERCA钙泵和NKA钠泵。这是一类被称为“离子动力ATPase”的蛋白质中的两种，这种酶利用三磷酸腺苷的能量将离子泵过细胞膜。离子泵在所有细胞中都扮演着重要的角色，这些酶的功能失调与包括心力衰竭在内的人类疾病有关。这项拟议的研究将使用先进的荧光方法来测量活的心肌细胞中离子泵的结构和运动。我们将检验三个主要假设：1)离子泵经历非常大的结构变化。2)这些大的、缓慢的变化受快速蛋白质动力学的调节。3)调节伙伴以快速的动力学不断地与泵结合和解除结合。通过测量活的心肌细胞中的ATPase结构和运动，我们将对衰竭心肌的破坏机制有新的认识。 公共卫生相关性：离子泵在人类健康中占据核心地位，它们是包括心力衰竭在内的几种重要疾病过程中治疗干预的关键目标。本文主要研究两种离子泵：钠泵(NKA)和钙泵(SERCA)。NKA功能紊乱与肥厚和心力衰竭有关。用抑制药物靶向这个泵是治疗衰竭心脏收缩能力不足的最古老和最有效的治疗方法之一。SERCA负责泵送钙离子，这种离子协调心肌的收缩和松弛。最佳的钙处理对正常的心脏功能至关重要，SERCA活性紊乱被认为是心力衰竭的原因和结果。对这些结构相似的泵进行比较，将有助于深入了解常见的功能机制，并可能揭示干预心脏病过程的新机会。

DESCRIPTION (provided by applicant): The proposed research focuses on the SERCA calcium pump and the NKA sodium pump. These are two of a class of proteins called "Ion-motive ATPases", enzymes that use the energy of ATP to pump ions across cell membranes. Ion pumps play an important role in all cells, and disordered function of these enzymes is associated with human disease, including heart failure. The proposed research will use advanced fluorescence methods to measure the structures and motions of ion pumps in living cardiac muscle cells. We will test three major hypotheses: 1) Ion pumps undergo very large structure changes. 2) These large slow changes are regulated by fast protein dynamics. 3) Regulatory partners continually bind and unbind from the pump with fast kinetics. By measuring ATPase structures and motions in live cardiac cells, we will gain new insight into mechanisms that become disrupted in failing cardiac muscle. PUBLIC HEALTH RELEVANCE: Ion pumps occupy a central position in human health, and they are key targets for therapeutic intervention in several important disease processes including heart failure. This research focuses on two ion pumps: the sodium pump (NKA) and the calcium pump (SERCA). Disordered NKA function is associated with hypertrophy and heart failure. Targeting this pump with inhibitory drugs is one of the oldest and most effective treatments for the inadequate contractility of the failing heart. SERCA is responsible for pumping calcium, the ion that coordinates the contraction and relaxation of the cardiac muscle. Optimal calcium handling is critical for normal cardiac function, and deranged SERCA activity has been implicated as a cause and an effect of heart failure. A comparison of these structurally similar pumps will yield insight into common functional mechanisms, and may reveal new opportunities to intervene in the process of heart disease.