Mori Y, Takada N, Okada T, Wakamori M, Imoto K, Wanifuchi H, Oka H, Oba A, Ikenaka K, Kurosaki T
Department of Information Physiology, National Institute for Physiological Sciences, Okazaki, Japan.
Neuroreport. 1998 Feb 16;9(3):507-15.
Mammalian homologues of the Drosophila TRP proteins, which are essential for light-activated, phosphatidyl-inositide (PI)-dependent Ca2+ conductance in Drosophila photoreceptors, were molecularly identified, to investigate receptor-activated Ca2+ influx in the mammalian nervous system. Two cloned mouse TRP homologues, TRP3 and TRP4, structurally related to the voltage-dependent Na+ channel, were expressed predominantly in the brain, where a sharp contrast in the distribution of the RNA transcripts for TRP isoforms was demonstrated by in situ hybridization analysis. TRP3 mRNA was concentrated in cerebellar Purkinje cells and sparsely localized in the cerebellar granule layer, pontine nuclei, and thalamus, whereas TRP4 mRNA was abundantly expressed in hippocampal CA1 pyramidal neurons, dentate gyrus granule cells, and cerebral cortical neurons, and in the septal nuclei and the mitral layer of olfactory bulb. The distinct spatial patterns of TRP isoforms implicate that neurons are highly heterogeneous in receptor-activated Ca2+ influx responsible for the second phase of PI-mediated rise in intracellular Ca2+.
果蝇TRP蛋白对于果蝇光感受器中光激活的、磷脂酰肌醇（PI）依赖性Ca2+传导至关重要，其哺乳动物同源物已被分子鉴定，以研究哺乳动物神经系统中受体激活的Ca2+内流。两个克隆的小鼠TRP同源物TRP3和TRP4与电压依赖性Na+通道在结构上相关，主要在脑中表达，原位杂交分析显示TRP亚型的RNA转录本分布存在明显差异。TRP3 mRNA集中在小脑浦肯野细胞中，并稀疏地定位于小脑颗粒层、脑桥核和丘脑，而TRP4 mRNA在海马CA1锥体神经元、齿状回颗粒细胞和大脑皮层神经元以及隔核和嗅球的二尖瓣层中大量表达。TRP亚型的独特空间模式表明，在负责PI介导的细胞内Ca2+升高第二阶段的受体激活Ca2+内流方面，神经元具有高度异质性。
