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Regulatory mechanism in gene expression of regulatory proteins in cardiac and vascular smooth muscles

心脏和血管平滑肌调节蛋白基因表达的调节机制

基本信息

批准号：
01480249
负责人：
HIWADA Kunio
金额：
$ 4.16万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01480249/
关键词：
calponin thin filament actomyosin MgATPase SM22 SM22cDNA cloning calponin cDNA cloning chicken gizzard rat aorta 血管平滑筋 cDNAクロ-ニングラット大動脈細い線維平滑筋ミオシン軽鎖MgATPase cDNA SM22α ミオシン軽鎖MgATPase活性ウシ大動脈

项目摘要

Calponin is actin-, tropomyosin binding protein which we found in the smooth muscle cells. In this project we studied the localization of calponin in smooth muscle cell and the physiological function of calponin.(1) We obtained thin filaments which contained actin, tropomyosin, caldesmon and calponin in molar rations of 7 : 0.9 : 0.6 : 0.7. Co-localization of actin and calponin was shown along stress fibers of smooth muscle cells from rat aorta.(2) We studied the function of calponin in vitro. Calponin inhibited the actinactivated myosin MgATPase activity in a dose-dependent manner. This inhibition was Ca-independent. The decrease in enzymatic activity of myosin was correlated with binding of calponin to actin-tropgmypsin filaments. Caldesmon showed a further inhibition of the calponin-induced inhibition of MgATPase activity of the thiophosphorylated myosin. Calponin-induced inhibition of the myosin MgATPase was reversed by the addition of calmodulin in the presence of Ca. These results suggest that calponin acts as an inhibitory component of smooth muscle thin filaments.(3) We performed cDNA cloning of SM22 from the chicken gizzard smooth muscle and rat aorta smooth muscle. Cloned cDNA encoding SM22 from the chicken gizzard smooth muscle had a total length of 1214bp and contained a single open reading frame which encodes 200 amino acids with a calculated molecular weight 22214. The predicted amino acid sequence was in complete agreement with the sequence determined by Pearlstone et al. who discovered the protein, except for two additional residues, isoleucine and serine at the C-terminus. The cDNA from rat aorta was 1186bp. in length and encoded 201 amino acids (Mr 22602). The predicted amino acid sequence showed an 85% Tdentity with the chicken gizzard SM22.

Calponin是一种存在于平滑肌细胞中的肌动蛋白、原肌球蛋白结合蛋白。本课题研究了钙调蛋白在平滑肌细胞中的定位及其生理功能。(1)我们获得了含有肌动蛋白、原肌球蛋白、钙调蛋白和钙调蛋白的细丝，其摩尔比为7：0.9：0.6：0.7。肌动蛋白和钙调蛋白共定位于大鼠主动脉平滑肌细胞的沿着应力纤维。(2)我们在体外研究了钙调蛋白的功能。Calponin呈剂量依赖性抑制肌动蛋白激活的肌球蛋白MgATPase活性。这种抑制作用不依赖于钙离子。肌球蛋白酶活性的降低与钙调蛋白与肌动蛋白-tropgmypsin丝的结合有关。Caldesmon进一步抑制了钙调蛋白诱导的硫代磷酸化肌球蛋白MgATPase活性抑制。钙调蛋白诱导的肌球蛋白MgATP酶的抑制被逆转的钙调蛋白的存在下加入钙。这些结果表明，钙调蛋白作为平滑肌细丝的抑制成分。(3)我们从鸡砂囊平滑肌和大鼠主动脉平滑肌中克隆了SM 22的cDNA。从鸡的砂囊平滑肌中克隆了SM 22的cDNA，全长1214 bp，含有一个开放阅读框，编码200个氨基酸，分子量为22214。预测的氨基酸序列与Pearlstone等人确定的序列完全一致，Pearlstone等人发现了该蛋白质，除了两个额外的残基，C-末端的异亮氨酸和丝氨酸。大鼠主动脉cDNA全长1186 bp。编码201个氨基酸（Mr 22602）。预测的氨基酸序列与鸡砂囊SM 22的同源性为85%。