MOLECULAR-CLONING AND CHARACTERIZATION OF A NOVEL TRUNCATED FORM (C1C-2-BETA) OF CLC-2-ALPHA - (CIC-2G) IN RABBIT HEART
MOLECULAR-CLONING AND CHARACTERIZATION OF A NOVEL TRUNCATED FORM (C1C-2-BETA) OF CLC-2-ALPHA - (CIC-2G) IN RABBIT HEART
复制标题
DOI：
10.1016/0014-5793(95)01178-h
复制
发表时间：
1995-11-13
期刊：
影响因子：
3.5
通讯作者：
HIRAOKA, M
中科院分区：
文献类型：
--
作者：
FURUKAWA, T;HORIKAWA, S;HIRAOKA, M
通过聚合酶链反应（PCR）克隆策略分离出了两种编码兔心脏氯离子通道的互补DNA（cDNA）（rabClC - 2β和rabClC - 2α）。RabClC - 2β是一种新的cDNA，由2998个碱基对组成，编码822个氨基酸的蛋白质，而rabClC - 2α与先前报道的ClC - 2G相同。RabClC - 2β从rabClC - 2α的氨基末端截短了68个氨基酸，但所有13个假定的疏水结构域在rabClC - 2β中都保守存在。尽管有人认为rabClC - 2α可被细胞外低渗激活，但在非洲爪蟾卵母细胞中表达rabClC - 2β时，即使在没有细胞外低渗的情况下也能诱导出大的氯离子电流。诱导细胞外低渗并不能进一步增加膜电流的幅度。另一方面，与rabClC - 2α相似，rabClC - 2β电流可因蛋白激酶A（PKA）的激活而增强。因此，同一基因的不同RNA加工过程似乎在兔心脏中提供了两种高度同源的、受PKA激活的氯离子通道，它们对细胞肿胀有或没有反应。
Two cDNAs encoding rabbit heart Cl- channels (rabClC-2 beta and rabClC-2 alpha) were isolated by a PCR cloning strategy, RabClC-2 beta is a novel cDNA consisting of 2998 bp and encoding the 822-amino acid protein, while rabClC-2 alpha is identical to previously reported ClC-2G, RabClC-2 beta is 68 amino acids truncated from NH2-terminus of rabClC-2 alpha, but all 13 putative hydrophobic domains are conserved in rabClC-2 beta. Although rabClC-2 alpha was suggested to be activated by extracellular hypotonicity, expression of rabClC-2 beta in Xenopus oocytes induced large Cl- currents even in the absence of extracellular hypotonicity, Induction of external hypotonicity did not further increase the amplitude of membrane currents, On the other hand, as similar to rabClC-2 alpha, rabClC-2 beta current was augmented by PKA activation, Thus, different RNA processing of the same gene appears to provide two highly homologous PKA-activated Cl- channels with or without responsiveness to cell swelling in rabbit heart.