Plasma membrane calcium pump isoform 4a has a longer calmodulin-binding domain than 4b.
Plasma membrane calcium pump isoform 4a has a longer calmodulin-binding domain than 4b.
复制标题
质膜钙泵同工型 4a 具有比 4b 更长的钙调蛋白结合结构域。
DOI：
10.1074/jbc.271.7.3714
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Penniston,JT
中科院分区：
文献类型：
--
作者：
Verma,AK;Enyedi,A;Filoteo,AG;Strehler,EE;Penniston,JT
Alternate splicing of human plasma membrane calcium pump isoform 4 (hPMCA4) transcripts causes the expression of two variants, hPMCA4a and hPMCA4b, which have different downstream regulatory regions. Of the two, hPMCA4a has a lower affinity for calmodulin and a lower effective affinity for Ca2+(Enyedi, A., Verma, A. K., Heim, R., Adamo, H. P., Filoteo, A. G., Strehler, E. E., and Penniston, J. T.(1994)J. Biol. Chem.269, 41-43). Additional consequences of the alternate splice were studied by analyzing the characteristics of constructs (expressed in COS-1 cells) containing different portions of the carboxyl terminus of hPMCA4a. Our results show striking differences in the structure of the calmodulin-binding and autoinhibitory domains of the two variants. The calmodulin-binding region of hPMCA4b is a region of about 28 residues, whereas that of hPMCA4a is about 49 residues long and is probably interrupted by a region not involved in the binding. The autoinhibitory region of hPMCA4b (a part of the downstream region that keeps the molecule inactive in the absence of Ca2+-calmodulin) is divided between the 28-residue calmodulin-binding region and a downstream region, whereas in hPMCA4a, all of it is contained within the 49-residue calmodulin-binding region.
