Differential expression and alternative splicing of TRP channel genes in smooth muscles
Differential expression and alternative splicing of TRP channel genes in smooth muscles
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DOI：
10.1152/ajpcell.2001.280.5.c1184
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发表时间：
2001-05-01
影响因子：
5.5
通讯作者：
Horowitz, B
中科院分区：
文献类型：
--
作者：
Walker, RL;Hume, JR;Horowitz, B
非选择性阳离子通道（NSCC）是平滑肌兴奋性激动剂的作用靶点，代表非选择性阳离子电流I-cat。Na+通过NSCC内流引起去极化并激活电压依赖性Ca ~（2+）通道，导致收缩。Icat在平滑肌中的分子身份尚未阐明，然而，产品的瞬时受体电位（TRP）基因具有类似于本地I-cat的特点。我们已经确定了TRP转录表达水平在几个小鼠和犬的胃肠道和血管平滑肌，并分析了这些成绩单的替代加工。在7个TRP基因家族成员中，在所有鼠和犬平滑肌细胞制备物中检测到TRP 4、TRP 6和TRP 7的转录物。TRP 3仅在犬肾动脉平滑肌细胞中检测到。从小鼠结肠平滑肌中克隆了TRP 4、TRP 6和TRP 7的全长cDNA，以及TRP 4的一个剪接变体和TRP 7的两个剪接变体。定量RT-PCR测定了几种小鼠平滑肌中TRP 4、TRP 6和TRP 7转录物以及剪接变体的相对量。TRP 4是最高表达的，而TRP 6和TRP 7在相同组织中以较低水平表达。剪接变体TRP 7，删除外显子编码的氨基酸，包括跨膜段S1，占主导地位的小鼠平滑肌，而全长形式的转录本在犬平滑肌中表达。
Nonselective cation channels (NSCC) are targets of excitatory agonists in smooth muscle, representing the nonselective cation current I-cat. Na+ influx through NSCC causes depolarizations and activates voltage-dependent Ca2+ channels, resulting in contraction. The molecular identity of Icat in smooth muscle has not been elucidated; however, products of the transient receptor potential (TRP) genes have characteristics similar to native I-cat. We have determined the levels of TRP transcriptional expression in several murine and canine gastrointestinal and vascular smooth muscles and have analyzed the alternative processing of these transcripts. Of the seven TRP gene family members, transcripts for TRP4, TRP6, and TRP7 were detected in all murine and canine smooth muscle cell preparations. TRP3 was detected only in canine renal artery smooth muscle cells. The full-length cDNAs for TRP4, TRP6, and TRP7, as well as one splice variant of TRP4 and two splice variants of TRP7, were cloned from murine colonic smooth muscle. Quantitative RT-PCR determined the relative amounts of TRP4, TRP6, and TRP7 transcripts, as well as that of the splice variants, in several murine smooth muscles. TRP4 is the most highly expressed, while TRP6 and TRP7 are expressed at a lower level in the same tissues. Splice variants for TRP7, deleted for exons encoding amino acids including transmembrane segment S1, predominated in murine smooth muscles, while the full-length form of the transcript was expressed in canine smooth muscles.