Evidence for the presence of calsequestrin in two structurally different regions of myocardial sarcoplasmic reticulum
Evidence for the presence of calsequestrin in two structurally different regions of myocardial sarcoplasmic reticulum
复制标题
心肌肌浆网两个结构不同区域存在钙螯合蛋白的证据
作者：
A. O. Jorgensen;K. Campbell
用间接免疫荧光法和免疫蛋白A-胶体金标记法分别测定了鸡心室肌细胞内钙螯合蛋白的定位。钙螯合蛋白定位于外周连接肌浆网的内腔中，以及存在于I带的中心区域中的膜结合结构的内腔中，而在心肌细胞的A带区域中的肌浆网内腔中不存在。由于鸡心室肌细胞缺乏横小管，钙螯合蛋白的存在下，在中央区域的I-带的膜结合结构表明，这些细胞含有非交界区的肌浆网，参与钙储存和可能的钙释放。可能的是，肌细胞的I带区域中存在的含钙螯合蛋白的结构对应于I带中的游离肌浆网的专门区域，称为Corbular肌浆网。这将是感兴趣的，以确定是否Ca 2+存储和可能的Ca 2+释放的连接和非连接区的肌浆网在鸡心室肌细胞的调节由相同或不同的生理信号。
Localization of calsequestrin in chicken ventricular muscle cells was determined by indirect immunofluorescence and immuno-Protein A- colloidal gold labeling of cryostat and ultracryotomy sections, respectively. Calsequestrin was localized in the lumen of peripheral junctional sarcoplasmic reticulum, as well as in the lumen of membrane- bound structures present in the central region of the I-band, while being absent from the lumen of the sarcoplasmic reticulum in the A-band region of the cardiac muscle cells. Since chicken ventricular muscle cells lack transverse tubules, the presence of calsequestrin in membrane bound structures in the central region of the I-band suggests that these cells contain nonjunctional regions of sarcoplasmic reticulum that are involved in Ca2+ storage and possibly Ca2+ release. It is likely that the calsequestrin containing structures present throughout the I-band region of the muscle cells correspond to specialized regions of the free sarcoplasmic reticulum in the I-band called corbular sarcoplasmic reticulum. It will be of interest to determine whether Ca2+ storage and possibly Ca2+ release from junctional and nonjunctional regions of the sarcoplasmic reticulum in chicken ventricular muscle cells are regulated by the same or different physiological signals.
DOI：
10.1007/978-1-4615-9296-9_5
发表时间：
1983
期刊：
Cell and muscle motility
影响因子：
--
作者：
M. Forbes;N. Sperelakis
通讯作者：
M. Forbes;N. Sperelakis