Kimura T, Shouno O, Hirota K, Saito T, Matsumoto G, Sato C
Supermolecular Science Division, Electrotechnical Laboratory, Tsukuba, Japan.
Biochem Biophys Res Commun. 1997 Jan 3;230(1):147-54. doi: 10.1006/bbrc.1996.5732.
The complete amino acid sequence of a putative calcium channel alpha1-subunit, SQCC1, from the optic lobe of the squid Loligo bleekeri has been deduced by cloning and sequence analysis of the complementary DNA. The open reading frame encodes 2206 amino acids, which corresponds to a molecular weight of 251,451. The deduced amino acid sequence shares general structural features with the other voltage-dependent calcium channels; it consists of four repeated units of homology. Each motif has five hydrophobic segments and one positively charged segment. The transcriptional products were detected in all nervous systems examined; optic lobe, cerebral ganglia and giant stellate ganglia. However, it was not detected in the mantle muscle, heart and stomach, indicating SQCC1 is a calcium channel alpha1-subunit specific for squid nervous system. SQCC1 is more closely related in its amino acid sequence patterns to dihydropyridine-insensitive calcium channels rather than dihydropyridine-sensitive ones.
通过对鱿鱼（剑尖枪乌贼）视叶中假定的钙通道α1亚基SQCC1的互补DNA进行克隆和序列分析，已推导得到其完整的氨基酸序列。开放阅读框编码2206个氨基酸，对应的分子量为251,451。推导得到的氨基酸序列与其他电压依赖性钙通道具有共同的结构特征；它由四个重复的同源单位组成。每个基序有五个疏水片段和一个带正电荷的片段。在所检测的所有神经系统中均检测到转录产物；视叶、脑神经节和巨大星状神经节。然而，在外套膜肌肉、心脏和胃中未检测到，这表明SQCC1是鱿鱼神经系统特有的钙通道α1亚基。SQCC1的氨基酸序列模式与二氢吡啶不敏感的钙通道而非二氢吡啶敏感的钙通道更为密切相关。
