Studies on molecular structure of C-protein and its role in myofibrillogensis

C蛋白分子结构及其在肌原纤维形成中的作用研究

基本信息

批准号：
06454024
负责人：
OBINATA Takashi
金额：
$ 4.35万
依托单位：
CHIBA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

C-protein is a major myosin-binding protein involved in myosin assembly and registration of thick filaments in the sarcomeres during myofibrillogenesis. Distinct C-protein isoforms, fast (F), slow (S), and cardiac (C), are present in both chicken and mammals, and C-isoform is known to be first expressed during chicken muscle development. The present studies were carried out aiming to clarify the molecular structure of C-protein and its role in myofibrillogensis, and the following results were obtained.1) The complete cDNA sequence encoding chicken cardiac (C) C-protein and the deduced amino acid sequence were determined. Seven IgC2 domains, 3 fibronectin type III domains and a phosphorylation site were specified in the molecule and the C-terminal IgC2 was designated to be essential for myosin-binding. In addition, two variants of C isoform which differ only in the presence or absence of the phosphorylation site were detected. Both were detected in cardiac muscle through developmental s … More tages, while only the latter was in embryonic skeletal muscle.2) In order to clarify expression pattern of C-protein isoforms and their roles in mammalian muscle development, the cDNAs encoding mouse skeletal muscle (F and S) C-protein were cloned and determined the entire sequences. In adult mouse tissues, the messages for C-, F-, S- isoforms were detected in a tissue-specific fasion by Northern blotting ; interestingly, however, both F- and S-isoforms were detectable in EDL (extensor digitorum longus) muscle which has been categorized as a typical fast muscle. Although C-isoform is known to be expressed first and transiently during development of chicken skeletal muscles, C-isoform was not detected at all in mouse skeletal muscle through developmental stages, but S-isoform became detectable first, followed by appearance of F-isoform. Basically the same results were obtained at a protein level by means of Western blot and indirect immunofluorescence methods with isoform-specific antibodies. Less

C蛋白是肌动蛋白组装和肌纤维中厚细丝的主要结合蛋白，在肌原纤维发生过程中。鸡肉和哺乳动物均存在不同的C蛋白亚型，快速（F），慢速（S）和心脏（C），并且C-异型成型在鸡肉肌肉发育过程中首次表达。进行了目前的研究，目的是阐明C蛋白的分子结构及其在肌原纤维发生中的作用，并获得以下结果。1）确定编码鸡心脏（C）C蛋白的完整cDNA序列，并确定了氨基酸序列。在分子中指定了七个IgC2结构域，3个纤连蛋白III型结构域和一个磷酸化位点，并指定C末端IgC2对于肌球蛋白结合至关重要。此外，仅检测到仅在存在或不存在磷酸化位点的存在或不存在的两个C同工型的变体。两者在心脏肌肉中通过发育s进行了……更多的标签，而后者仅在胚胎骨骼肌中。在成年小鼠组织中，通过北面印迹检测到在组织特异性的伪造中检测到C-，F-，S-同工型的信息。然而，有趣的是，在EDL（伸肌长肌）肌肉中都可以检测到F-和S-异类型，该肌肉已被归类为典型的快速肌肉。尽管已知在鸡骨骼肌发育过程中首先和瞬时表达C-异型，但在小鼠骨骼肌中，通过发育阶段根本没有检测到C-异型，但S-异型成型型首先可以检测到，其次是F-Esoform的出现。基本上，通过蛋白质水平和间接免疫荧光方法，具有同工型特异性抗体，在蛋白质水平上获得了相同的结果。较少的