Signal transduction with special reference to myosin

信号转导，特别涉及肌球蛋白

• 批准号: 02454132
• 负责人: KOHAMA Kazuhiro
• 金额: $ 3.9万
• 依托单位: Gunma University School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02454132/
• 关键词: myosin; Calcium; kinase; myosin light chain; myosin heavy chain; physarum polycephalum; アクチン; 細胞内情報伝達

ATP-dependent interactions between myosin and actin in the lower eucaryote, Physarum polycephalum, are inhibited by micromolar levels of Ca^<2+>. This inhibition is mediated by the binding of Ca^<2+> to myosin, the phosphorylation of which is required if Ca^<2+> is to inhibit the activities of myosin. As the first step to examine whether Ca^<2+> also regulates phosphorylation in the actomyosin system, we purified myosin light chain kinase (MLCK) of 55 kDa almost to homogeneity. The MLCK activity was high whether or not Ca^<2+> was present. A Ca^<2+>-dependent inhibitory factor (CIF) of 38 kDa was purified from Physarum. We showed that CIF was effective to reduce the MLCK activity in a Ca^<2+>-dependent manner.Using crude preparations, not only MLCK but also myosin heavy chain kinase and actin kinase were shown to be inhibited by Ca^<2+> half-maximally at micromolar levels. Since CIF is the only Ca^<2+>-binding protein in the preparations, we propose that this inhibitory Ca^<2+>-regulation of the kinases for actomyosin is mediated by CIF.

低等真核生物多头绒泡菌中肌球蛋白和肌动蛋白之间的ATP依赖性相互作用被微摩尔水平的Ca 2+ 抑制。这种抑制是通过Ca 2+ 与肌球蛋白的结合介导的，如果Ca 2+ 想要抑制肌球蛋白的活性，则需要肌球蛋白的磷酸化。作为检查Ca 2+ 是否也调节肌动球蛋白系统中的磷酸化的第一步，我们将55kDa的肌球蛋白轻链激酶(MLCK)纯化至几乎同质。无论Ca 2+ 是否存在，MLCK活性都很高。从绒泡菌中纯化出38kDa的Ca 2+ 依赖性抑制因子(CIF)。我们证明CIF能够以Ca^2+依赖性方式有效降低MLCK活性。使用粗制剂，不仅MLCK而且肌球蛋白重链激酶和肌动蛋白激酶在微摩尔水平下都被Ca^2+半最大抑制。由于CIF是制剂中唯一的Ca 2+ 结合蛋白，我们推测肌动球蛋白激酶的这种抑制性Ca 2+ 调节是由CIF介导的。

项目成果

Kohno, T., Okagaki, T., Kohama, K. and Shimmen, T.: "Pollen tube extract supports the movement of actin filaments in vitro." Protoplasma. 161. 75-77 (1991)

Kohno, T.、Okagaki, T.、Koham, K. 和 Shimmen, T.：“花粉管提取物支持肌动蛋白丝在体外的运动。”

Okagaki,T.,Ishikawa,R.and Kohama,K.: "Purification of a novel Caーbinding protein that inhibits myosin light chain kinase activity in lower eukaryote,Physarum polysephalum." Biochemical Biophysical Research Communication. 176. 564-570 (1991)

Okagaki, T.、Ishikawa, R. 和 Kohama, K.：“抑制低等真核生物多隔菌中肌球蛋白轻链激酶活性的新型碳结合蛋白的纯化”，176. 564-570 (1991)。

Okagaki,T.,Ishikawa,R.and Kohama,K.: "Purification of a novel Ca-binding protein that inhibits myosin light chain kinase activity in lower eukaryote,physarum polycephalum" Biochemical Biophysical Research Communication. 176. 564-570 (1991)

Okagaki,T.、Ishikawa,R. 和 Kohama,K.：“纯化一种新型 Ca 结合蛋白，可抑制低等真核生物多头绒泡菌中的肌球蛋白轻链激酶活性”生化生物物理研究通讯。

Okagaki,T.,Ishikawa,R.and Kohama,K.: "Inhibitory Ca^<2+>-regulation of myosin light chain kinase in the lower eukaryote,Physarum polycephalum: role of a ca^<2+>-dependent inhibitory factor." European Journal of Cell Biology. 56. 113-122 (1991)

Okagaki,T.、Ishikawa,R.和 Kohama,K.：“低等真核生物多头绒泡菌中肌球蛋白轻链激酶的抑制性 Ca^2 调节：ca^2 依赖性抑制因子的作用。

Okagaki, T., Ishikawa, R. and Kohama, K.: "Purification of a novel Ca-binding protein that inhibits myosin light chain kinase activity in lower eucaryote, Physarum polycephalum." Biochem. Biophys. Res. Commun.176. 564-570 (1991)

Okagaki, T.、Ishikawa, R. 和 Kohama, K.：“纯化一种新型 Ca 结合蛋白，可抑制低等真核生物多头绒泡菌中的肌球蛋白轻链激酶活性。”