Rubenstein P A
Department of Biochemistry, University of Iowa College of Medicine, Iowa City 52242.
Bioessays. 1990 Jul;12(7):309-15. doi: 10.1002/bies.950120702.
Actin is a protein that plays an important role in cell structure, cell motility, and the generation of contractile force in both muscle and nonmuscle cells. In many organisms, multiple forms of actin, or isoactins, are found. These are products of different genes and have different, although very similar, amino acid sequences. Furthermore, these isoactins are expressed in a tissue specific fashion that is conserved across species, suggesting that their presence is functionally important and their behavior can be distinguished quantitatively from one another in vitro. In muscle cells, they are differentially distributed within the cell and some are specifically associated with structures such as costameres, mitochondria, and neuromuscular junctions. There is also good evidence for specific isoactin function in microvascular pericytes and in the intestinal brush border. However, the necessity of specific isoactins for various functions has not yet been conclusively demonstrated.
肌动蛋白是一种在细胞结构、细胞运动以及肌肉和非肌肉细胞收缩力产生过程中发挥重要作用的蛋白质。在许多生物体中，发现了多种形式的肌动蛋白，即同工肌动蛋白。这些是不同基因的产物，具有不同但非常相似的氨基酸序列。此外，这些同工肌动蛋白以组织特异性的方式表达，这种方式在物种间是保守的，这表明它们的存在在功能上很重要，并且它们的行为在体外可以相互定量区分。在肌肉细胞中，它们在细胞内有不同的分布，有些与诸如肌小节、线粒体和神经肌肉接头等结构特异性相关。在微血管周细胞和肠刷状缘中也有关于特定同工肌动蛋白功能的充分证据。然而，特定同工肌动蛋白对各种功能的必要性尚未得到确凿证明。
