Cloning of a C-terminally truncated NK-1 receptor from guinea-pig nervous system
Cloning of a C-terminally truncated NK-1 receptor from guinea-pig nervous system
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DOI：
10.1016/s0169-328x(03)00002-0
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发表时间：
2003-03-17
期刊：
影响因子：
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通讯作者：
Gibbins, IL
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文献类型：
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作者：
Baker, SJ;Morris, JL;Gibbins, IL
为了探讨P物质的某些作用可能是由神经激肽-1(NK-1)受体的一个变异体介导的可能性，我们采用3‘RACE方法，采用两步RT-PCR方法，从豚鼠腹腔神经节和脑中分离并测序了编码NK-1受体截短的基因。截短的NK-1受体序列对应于缺失最后一个外显子5的剪接变异体，编码一个31I氨基酸的蛋白质，该蛋白质在跨膜区7之后被截断，其位置与人NK-1受体的截断变异体相同。因此，截短的NK-1受体缺乏全长NK-1受体磷酸化和内化所需的细胞内C末端序列。使用灵敏的一步半定量RT-PCR方法，我们检测了大脑、脊髓、感觉和自主神经节以及内脏中全长和截短的NK-1受体的mRNA。截短的NK-1受体mRNA在所有组织中的表达均低于全长NK-1R的mRNA。截短的NK-1受体在腹神经节、脊髓、基底节和下丘脑中表达水平最高。NK-1受体N端的抗血清标记了未标记全长NK-1受体C端抗血清的腹腔神经节神经元的树突。这些结果表明，NK-1受体的C端截短变体很可能在中枢和周围神经组织中广泛存在。我们预测，在缺乏全长NK-1受体的免疫组织化学证据的情况下，这种受体将介导P物质对神经元的作用。(C)2003 Elsevier Science B.V.保留所有权利。
In order to examine the possibility that some actions of substance P may be mediated by a variant of the neurokinin-1 (NK-1) receptor, we isolated and sequenced the cDNA encoding a truncated NK-1 receptor from guinea-pig celiac ganglion and brain mRNA by two-step RT-PCR based on the 3'RACE method. The truncated NK-1 receptor sequence corresponded to a splice variant missing the final exon 5, and encoded a 31 I-amino acid protein that was truncated just after transmembrane domain 7, in an identical position to a truncated variant of the human NK-1 receptor. Thus, the truncated NK-1 receptor lacked the intracellular C-terminus sequence required for the phosphorylation and intemalisation of the full-length NK-1 receptor. Using a sensitive one-step semi-quantitative RT-PCR assay, we detected mRNA for both the full length and truncated NK-1 receptors throughout the brain, spinal cord, sensory and autonomic ganglia, and viscera. Truncated NK-1 receptor mRNA was present in lower quantities than mRNA for the full-length NK-1 R in all tissues. Highest levels of mRNA for the truncated NK-1 receptor were detected in coeliac ganglion, spinal cord, basal ganglia and hypothalamus. An antiserum to the N-terminus of the NK-1 receptor labelled dendrites of coeliac ganglion neurons that were not labelled with antisera to the C-terminus of the full length NK-1 receptor. These results show that a C-terminally truncated variant of the NK-1 receptor is likely to be widespread in central and peripheral nervous tissue. We predict that this receptor will mediate actions of substance P on neurons where inummohistochemical evidence for a full-length NK-1 receptor is lacking. (C) 2003 Elsevier Science B.V. All rights reserved.