VINCULIN IS A COMPONENT OF AN EXTENSIVE NETWORK OF MYOFIBRIL-SARCOLEMMA ATTACHMENT REGIONS IN CARDIAC-MUSCLE FIBERS
VINCULIN IS A COMPONENT OF AN EXTENSIVE NETWORK OF MYOFIBRIL-SARCOLEMMA ATTACHMENT REGIONS IN CARDIAC-MUSCLE FIBERS
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DOI：
10.1083/jcb.97.4.1081
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发表时间：
1983-01-01
影响因子：
7.8
通讯作者：
CRAIG, SW
中科院分区：
文献类型：
--
作者：
PARDO, JV;SILICIANO, JD;CRAIG, SW
免疫荧光染色的牛和禽的心脏组织与亲和纯化抗体的鸡砂囊黏着斑蛋白揭示了2个新的网站黏着斑蛋白的反应。首先，黏着斑蛋白在肌膜上排列成一系列引人注目的肋状带或肋节。中肋肌垂直于纤维长轴环绕心肌细胞，并覆盖紧邻下胫肌节的I带。纽蛋白反应的第二个新位点发现于牛心肌细胞质膜的小管内陷处。这些内陷的频率和位置对应于牛心房、心室和浦肯野纤维中横管系统的已知频率和分布。在禽类心肌细胞中没有发现用抗粘蛋白染色的小管内陷，事实上，在禽类心脏纤维中没有发现横向小管系统。在发现纽蛋白的同一区域，通过EM在心肌中观察到明显的肌膜侧向Z线附着及其内陷。根据这些先前的超微结构发现和已发表的肋肌之间物理连接的证据和骨骼肌中潜在的肌原纤维，本研究的免疫荧光数据被解释为意味着，在心肌中，黏着斑蛋白是肌原纤维侧向附着于质膜及其内陷的广泛系统的组分。
Immunofluorescent staining of bovine and avian cardiac tissue with affinity-purified antibody to chicken gizzard vinculin reveals 2 new sites of vinculin reactivity. First, vinculin is organized at the sarcolemma in a striking array of rib-like bands, or costameres. The costameres encircle the cardiac muscle cell perpendicular to the long axis of the fiber and overlie the I bands of the immediately subjacent sarcomeres. The 2nd new site of vinculin reactivity is found in bovine cardiocytes at tubular invaginations of the plasma membrane. The frequency and location of these invaginations correspond to the known frequency and distribution of the transverse tubular system in bovine atrial, ventricular and Purkinje fibers. Tubular invaginations that stain with antivinculin were not found in avian cardiocytes and, in fact, a transverse tubular system was not found in avian cardiac fibers. Apparent lateral Z-line attachments to the sarcolemma and its invaginations were observed in cardiac muscle by EM in the same regions where vinculin is found. On the basis of these previous ultrastructural findings and the published evidence for a physical connection between costameres and the underlying myofibrils in skeletal muscle, the immunofluorescence data of this study were interpreted to mean that, in cardiac muscle, vinculin is a component of an extensive system of lateral attachment of myofibrils to the plasma membrane and its invaginations.