Analyses of the functions of MYPT family, novel anchoring proteins, in cardiovascular system by their knockout and transgenic mice

通过敲除小鼠和转基因小鼠分析新型锚定蛋白 MYPT 家族在心血管系统中的功能

• 批准号: 12470152
• 负责人: NAKANO Takeshi
• 金额: $ 3.97万
• 依托单位: Mie University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12470152/
• 关键词: myosin phosphatase; MYPT1; MYPT2; knockout mouse; transgenic mouse; phosphorylation of cardiac myosin; Rhoキナーゼ; Proキナーゼ

MYPT is a target subunit of myosin phosphates (MP), in which MYPT interacts with a catalytic subunit (PP 1 cδ) and the other regulatory subunit, M20. MYPT could also interact with other molecules including RhoA and cGMP-dependent protein kinase Iα, indicating that MYPT has a role as an anchoring protein. MYPT1 is a target subunit of smooth muscle/nonmuscle MP and MYPT2 is that of cardiac/skeletal muscle MP. To investigate the in vivo function of MYPTs, we generated MYPT1-deficient mice and MYPT2 transgenic mice, and analyzed these phenotypesThe heterozygous of MYPT1-deficient mice showed no changes in the expression levels of MYPT1 and no phenotypes as compared with those in the wild type mice, however, none of the F2 mice was homozygous for the MYPT1 deletion, indicating that the targeted disruption of the MYPT1 gene results in embryonic lethality. The point of embryonic lethality is considered to be before 7.5 dpc. These findings indicate that MYPT1 is essential for mouse embryogenes … More isThe transgenic mice overexpressing MYPT2 (Tg) using α-MHC promoter demonstrated a significantly increased expression of MYPT2 (>20 folds) specifically in hearts with a concomitant increase of the endogenous PP1cδ. The phosphorylation levels of regulatory myosin light chain (RLC) in Tg were significantly lower than those in the wild type mice (Wt). These results suggest the specific in vivo interaction of MYPT2 with PP1cδ, which could dephosphorylate RLC in heart. Survival rate, body weight, heart rate and blood pressure were not significantly different between Tg and Wt. Heart weight/body weight ratio of Tg was significantly higher than that of Wt. Echocardiography demonstrated the dilation of LU dimension (LVDd and LVDs) and the moderate impairment of LV function in Tg. These results suggest that the overexpression of MYPT2 and the concomitant increased MP activity decreased LV contractility, resulting in mild LV dilatation. Taken together, MP seems to play a role in cardiac function in vivo Less

MYPT是肌球蛋白磷酸盐（MP）的靶亚基，其中MYPT与催化亚基（PP 1c δ）和另一个调节亚基M20相互作用。MYPT还可以与其他分子包括RhoA和cGMP依赖性蛋白激酶Iα相互作用，表明MYPT具有锚定蛋白的作用。MYPT 1是平滑肌/非肌肉MP的靶亚基，MYPT 2是心肌/骨骼肌MP的靶亚基。为了研究MYPTs的体内功能，我们制备了MYPT 1缺陷小鼠和MYPT 2转基因小鼠，并分析了这些表型。与野生型小鼠相比，MYPT 1缺陷小鼠的杂合子没有显示MYPT 1表达水平的变化，也没有显示表型，但是，没有一个F2小鼠是MYPT 1缺失的纯合子，表明MYPT 1基因的靶向破坏导致胚胎致死。胚胎致死点被认为是在7.5 dpc之前。这些发现表明MYPT 1对小鼠胚胎发生是必需的 ...更多信息 用α-MHC启动子过表达MYPT 2（Tg）的转基因小鼠心脏特异性MYPT 2表达显著增加（>20倍），同时内源性PP 1c δ也增加。Tg组调节性肌球蛋白轻链（RLC）磷酸化水平显著低于野生型小鼠（Wt）。这些结果表明MYPT 2与PP 1c δ在体内特异性相互作用，其可以使心脏中的RLC去磷酸化。Tg和Wt之间的存活率、体重、心率和血压没有显著差异。Tg组的心重/体重比显著高于Wt组。超声心动图显示Tg患者LU尺寸（LVDd和LVDs）扩张，LV功能中度受损。这些结果表明，MYPT 2的过度表达和伴随的MP活性增加降低了LV收缩力，导致轻度LV扩张。总之，MP似乎在体内心脏功能中发挥作用

项目成果

Shigemasa Araki: "Arachidonic acid-induced Ca^<2+> sensitization of smooth muscle contraction through activation of Rho-kinase"Pflugers Archiv.Eur.J.Physiol.. 441. 596-603 (2001)

Shigemasa Araki：“通过Rho激酶的激活，花生四烯酸诱导的Ca ^ 2 > 平滑肌收缩的敏化”Pflugers Archive.Eur.J.Physiol.. 441. 596-603 (2001)

Takafumi Koji: "Addition of angiotensin II receptor antagonist to ACE inhibitor in heart failure improves cardiovascular function by a bradykinin-mediated mechanism"J.Cardiovasc.Pharmacol.. 41. 632-639 (2003)

Takafumi Koji：“在心力衰竭中添加血管紧张素 II 受体拮抗剂至 ACE 抑制剂可通过缓激肽介导的机制改善心血管功能”J.Cardiovasc.Pharmacol.. 41. 632-639 (2003)

Harold Shirato, Hiroshi Shima, Gyosuke Sakashita, Takeshi Nakano, Masaaki Ito, Ernest Y C.Lee, Kunimi Kikuchi: "Identification and characterization of a novel protein inhibitor of type-1 protein phosphatase"Biochemistry. 39. 13848-13855 (2000)

Harold Shirato、Hiroshi Shima、Gyosuke Sakashita、Takeshi Nakano、Masaaki Ito、Ernest Y C.Lee、Kunimi Kikuchi：“1 型蛋白磷酸酶新型蛋白抑制剂的鉴定和表征”生物化学。

Testuya Seko: "Activation of RhoA and inhibition of myosin phosphatase as important components in hypertension in vascular Smooth muscle"Circulation Research. 92. 411-418 (2003)

Testuya Seko：“RhoA 的激活和肌球蛋白磷酸酶的抑制是血管平滑肌高血压的重要组成部分”循环研究。

Tetsuya Hamaguchi: "Phosphorylation of CPI-17, an inhibitory phosphoprotein of myosin phosphatase, by protein kinase N."Biochem.Biophys.Res.Commun.. 274. 825-830 (2000)

Tetsuya Hamaguchi：“蛋白激酶 N 对肌球蛋白磷酸酶的抑制性磷蛋白 CPI-17 进行磷酸化。”Biochem.Biophys.Res.Commun.. 274. 825-830 (2000)