Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia, Canada V6T 1Z3.
J Mol Cell Cardiol. 2013 May;58:22-31. doi: 10.1016/j.yjmcc.2012.11.022. Epub 2012 Dec 7.
L-type Ca(2+) channels and the Na(+)/Ca(2+) exchanger are the main pathways for Ca(2+) influx and efflux across the sarcolemma. The majority of Ca(2+) channels are found in couplons adjacent to ryanodine receptors, but there are at least two smaller, physically and functionally distinct, extradyadic populations. NCX is more widely dispersed in the membrane although a subpopulation is closely associated with the alpha-2 isoform of the Na(+)/K(+) ATPase and has a direct effect on ECC. In addition to Ca(2+) channels and ryanodine receptors, couplons in adult animals contain a variety of other occupants that modulate their function. These modulators can vary from one couplon to another creating a variety of molecular architectures. In this review we examine our current understanding of the molecular composition, binding partners and determinants of the localization of these proteins.
L 型钙通道和钠钙交换体是肌浆网上钙内流和外流的主要途径。大多数钙通道位于与兰尼碱受体相邻的偶联单位中，但至少还有两个较小的、在物理和功能上不同的非偶联单位。尽管钠钙交换体的亚群与钠钾 ATP 酶的α-2 同工型密切相关，并对 ECC 有直接影响，但它在膜中分布更广。除了钙通道和兰尼碱受体外，成年动物的偶联单位还包含多种其他调节其功能的成分。这些调节剂在不同偶联单位之间存在差异，从而形成了多种分子结构。在这篇综述中，我们研究了当前对这些蛋白质的分子组成、结合伴侣和定位决定因素的理解。
