Lehotský J
Comenius University, Jessenius Medical Faculty, Department of Biochemistry, Martin, Slovak Republic.
Mol Chem Neuropathol. 1995 Jun-Aug;25(2-3):175-87. doi: 10.1007/BF02960911.
The plasma membrane Ca(2+)-pump (PMCA) is a key element in the removal of intracellular Ca2+. A number of PMCA pumps, encoded by a multigenic family and differing in their regulatory domains, also exist in the neuronal cells. We discuss here an idea regarding a new, higher level of specialization of PMCA protein isoforms with different sensitivities toward phospholipids and calmodulin. The idea is based on the kinetic data from PMCA stimulation by acidic phospholipids, with a combination of results describing an alternative RNA splicing at site A and C coding of regulatory domains of protein. The resulting complex modulation of the Ca(2+)-pump underlies the specific cellular requirements for Ca2+ homeostasis in a tissue-selective manner and is regulated by the level and spatial distribution of enzyme isoforms as well as by the level of their regulatory factors. The possible role of PMCA protein in the neuronal injury is also discussed.
质膜钙泵（PMCA）是清除细胞内钙离子的关键元件。神经元细胞中也存在多个由多基因家族编码且调节结构域不同的PMCA泵。在此，我们探讨一种关于PMCA蛋白亚型具有不同磷脂和钙调蛋白敏感性的新的更高层次专业化的观点。该观点基于酸性磷脂刺激PMCA的动力学数据，并结合了描述蛋白质调节结构域在A和C位点的可变RNA剪接的结果。由此产生的钙泵复杂调节以组织选择性方式构成了细胞对钙离子稳态的特定需求基础，并受酶亚型的水平和空间分布及其调节因子水平的调控。还讨论了PMCA蛋白在神经元损伤中的可能作用。
