Molecular cloning and characterization of ryanodine receptor from unfertilized sea urchin eggs
Molecular cloning and characterization of ryanodine receptor from unfertilized sea urchin eggs
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DOI：
10.1152/ajpregu.00519.2001
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发表时间：
2002-03-01
影响因子：
2.8
通讯作者：
Ogawa, Y
中科院分区：
文献类型：
--
作者：
Shiwa, M;Murayama, T;Ogawa, Y
海胆（hemicentrrotus pulcherrimus）未受精卵表现出环adp核糖（cADPR）诱导的Ca2+释放和咖啡因诱导的Ca2+释放，两者都被认为是通过ryanodine受体（RyR）介导的。我们克隆了海胆卵RyR （suRyR）的cdna，该基因编码597 kda的蛋白，包含5317个氨基酸。suRyR与已知的RyRs具有共同的结构特征：保守性良好的cooh末端结构域，形成功能性的Ca2+通道，以及较大的亲水nh2末端结构域。suRyR的氨基酸序列与哺乳动物的RyR亚型相似（43-45%）。系统发育分析表明，suRyR在分化前从脊椎动物的三个亚型中分离出来，这表明suRyR可能是海胆中唯一的RyR亚型。在suRyR cdna中发现了四个框内插入，其中一个是新颖而独特的，因为它具有一簇丝氨酸残基。在卵子RNA中发现了有和没有这些插入的转录本。这些结果表明，suRyR可能作为一个功能Ca2+诱导的Ca2+释放通道表达，也可能参与cadpr诱导的Ca2+释放。
Unfertilized eggs of sea urchins (Hemicentrotus pulcherrimus) demonstrated cyclic ADP-ribose (cADPR)-induced Ca2+ release and caffeine-induced Ca2+ release, both of which were considered to be mediated through the ryanodine receptor (RyR). We cloned cDNAs for sea urchin egg RyR (suRyR), which encode a 597-kDa protein of 5,317 amino acids. suRyR shares common structural features with known RyRs: the well-conserved COOH-terminal domain, which forms a functional Ca2+ channel, and a large hydrophilic NH2-terminal domain. suRyR shows amino acid sequence identity (43-45%) similar to the three mammalian RyR isoforms. Phylogenetic analysis indicates that suRyR branched from three isoforms of vertebrates before they diverged, suggesting that suRyR may be the only RyR isoform in the sea urchin. Four in-frame insertions were found in suRyR cDNAs, one of which was novel and unique, in that it had a cluster of serine residues. The transcripts with and without these insertions were found in the egg RNA. These results suggest that suRyR may be expressed as a functional Ca2+ induced Ca2+ release channel, which might also be involved in cADPR-induced Ca2+ release.