ALTERED CALCIUM REGULATION IN CARDIOMYOPATHIES

心肌病中钙调节的改变

• 批准号: 6704225
• 负责人: P. Bryant Chase
• 金额: $ 32.74万
• 依托单位: FLORIDA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6704225
• 关键词: actins; binding sites; calcium flux; gene mutation; hypertrophic myocardiopathy; laboratory rabbit; laboratory rat; microfilaments; molecular pathology; phosphorylation; protein binding; protein structure function; troponin

DESCRIPTION (the applicant's description verbatim): Mutations in cardiac thin filament protein troponin I (cTnI) have been identified as causal in some forms of familial hypertrophic cardiomyopathy (FHC). The overall goal of this proposal is to characterize functional consequences of these six disease-related mutations in the C-terminus of cTnI. Specific predictions about their effects on steady-state force-pCa relationship derive from the localization of mutations in binding of TnI's C-terminus to: (i) the N-terminus of cTnC (R145G and R145Q mutations in the inhibitory peptide and R162W); or (ii) actin-Tm (R145G and R145Q mutations in the inhibitory peptide which is part of actin-Tm binding site I and K183delta which is part of actin-Tm binding site II). In addition, C-terminal truncation studies of TnI predict that R162W, K183delta, G203S and K206Q could all compromise the ability of cTn to relax the myocardium during diastole. Recombinant cTnI constructs will be altered with mutations found in FHC. Mutant and wild type (WT) constructs will be incorporated into permeabilized muscle preparations-for measurements of sarcomere mechanics-and into regulated actin filaments-for measurements on single actin filaments using in vitro motility assays. Mutant proteins will be tested, first by complete substitution of mutant for WT, secondly in varying proportions of WT and mutant as occurs in the diseased myocardium, and thirdly with additional mutations that mimic phosphorylation of Ser22 & Ser23 or Thr143 (introduction of acidic residues). For each mutation, we will determine the effects on Ca2+ sensitivity of steady-state isometric force, filament sliding, and the rate of tension redevelopment (kTR; a parameter that is important for evaluating cardiac function). The results will aid understanding normal Ca2+ regulation of the heart, pathological mechanism(s) of hypertrophy, and the assays will he useful for identifying treatments.

描述（申请人的逐字描述）：心脏薄层的突变 丝蛋白肌钙蛋白 I (cTnI) 已被确定为某些形式的因果关系 家族性肥厚型心肌病（FHC）。本次活动的总体目标 建议是描述这六个功能的功能后果 cTnI C 末端的疾病相关突变。具体预测如下 它们对稳态力-PCA 关系的影响源自 TnI 的 C 末端结合突变的定位： (i) N 末端 cTnC（抑制肽中的 R145G 和 R145Q 突变以及 R162W）；或者 (ii) 肌动蛋白-Tm（抑制肽中的 R145G 和 R145Q 突变， 肌动蛋白-Tm 结合位点 I 的一部分和 K183delta 是肌动蛋白-Tm 结合的一部分 站点二）。此外，TnI C 端截短研究预测 R162W、 K183delta、G203S 和 K206Q 都可能损害 cTn 松弛 舒张期期间的心肌。重组 cTnI 构建体将被改变 FHC 中发现的突变。突变型和野生型 (WT) 构建体将 纳入透化肌肉制剂中，用于测量 肌节力学 - 并进入调节的肌动蛋白丝 - 用于测量 使用体外运动测定的单肌动蛋白丝。突变蛋白将会 测试，首先通过突变体完全替代WT，其次在不同的 患病心肌中出现的 WT 和突变体的比例，第三 具有模拟 Ser22 和 Ser23 或 Thr143 磷酸化的额外突变 （引入酸性残基）。对于每个突变，我们将确定 稳态等长力、细丝滑动对 Ca2+ 敏感性的影响 和张力重建率（kTR；一个对于 评估心脏功能）。结果将有助于了解正常 Ca2+ 心脏的调节、肥厚的病理机制以及 化验将有助于确定治疗方法。

项目成果

Facilitated cross-bridge interactions with thin filaments by familial hypertrophic cardiomyopathy mutations in α-tropomyosin.

α-原肌球蛋白家族性肥厚型心肌病突变促进了与细丝的跨桥相互作用。

• DOI: 10.1155/2011/435271
• 发表时间: 2011
• 期刊: Journal of biomedicine & biotechnology
• 作者: Wang,Fang;Brunet,NicolasM;Grubich,JustinR;Bienkiewicz,EwaA;Asbury,ThomasM;Compton,LisaA;Mihajlović,Goran;Miller,VictorF;Chase,PBryant
• 通讯作者: Chase,PBryant

The functional significance of the last 5 residues of the C-terminus of cardiac troponin I.

• DOI: 10.1016/j.abb.2016.02.023
• 发表时间: 2016-07-01
• 期刊: Archives of biochemistry and biophysics
• 影响因子: 3.9
• 作者: Gilda JE;Xu Q;Martinez ME;Nguyen ST;Chase PB;Gomes AV
• 通讯作者: Gomes AV