Campbell A M, Kessler P D, Sagara Y, Inesi G, Fambrough D M
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218.
J Biol Chem. 1991 Aug 25;266(24):16050-5.
Two similar forms of the cardiac/slow Ca(2+)-ATPase (SERCA2a and SERCA2b), differing in sodium dodecyl sulfate-polyacrylamide gel electrophoresis mobility, are expressed in chicken heart and brain (Kaprielian, Z., Campbell, A. M., and Fambrough, D. M. (1989) Mol. Brain Res. 6, 55-60). In the current study, cDNAs encoding each form were cloned and sequenced. Chicken SERCA2a is 94% identical to its rabbit homologue, while SERCA2b has an extended carboxyl terminus with 38 of 49 amino acids identical to mammalian homologues. SERCA2b mRNA contains the SERCA2a encoding sequence within its 3'-untranslated region. Chicken genomic DNA sequence reveals that the alternate RNA splicing used to produced SERCA2a and SERCA2b subtypes involves a splice site within an exon. Tissue culture cells expressing the avian SERCA2a, SERCA2b, and SERCA1, each targetting to the endoplasmic reticulum, were used to measure Ca2+ affinities and inhibitor effects; no differences among the three pumps were detected.
心肌/慢钙（2+）-ATP酶的两种相似形式（SERCA2a和SERCA2b），在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳迁移率上存在差异，在鸡的心脏和大脑中表达（卡普列里安，Z.，坎贝尔，A.M.，和范布勒，D.M.（1989年）《分子脑研究》6，55 - 60）。在本研究中，编码每种形式的cDNA被克隆并测序。鸡的SERCA2a与其兔同源物有94%的同一性，而SERCA2b有一个延长的羧基末端，49个氨基酸中有38个与哺乳动物同源物相同。SERCA2b mRNA在其3'非翻译区内包含SERCA2a编码序列。鸡的基因组DNA序列显示，用于产生SERCA2a和SERCA2b亚型的可变RNA剪接涉及一个外显子内的剪接位点。表达禽类SERCA2a、SERCA2b和SERCA1（每种都靶向内质网）的组织培养细胞被用于测量钙亲和力和抑制剂作用；未检测到这三种泵之间的差异。
