Co-expression of metabotropic glutamate receptor type 1alpha with homer-1a/Vesl-1S increases the cell surface expression of the receptor.
Co-expression of metabotropic glutamate receptor type 1alpha with homer-1a/Vesl-1S increases the cell surface expression of the receptor.
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DOI：
10.1042/bj3410795
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发表时间：
1999-08
期刊：
影响因子：
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通讯作者：
F. Ciruela;M. Soloviev;R. Mcilhinney
中科院分区：
文献类型：
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作者：
F. Ciruela;M. Soloviev;R. Mcilhinney
Homer-1a是一个30 kDa的蛋白，是保守的Homer-1a相关蛋白家族的一部分，与代谢性谷氨酸受体mGluR1alpha和mGluR5a的c端相互作用。对HEK-293细胞进行PCR分析，发现其含有Homer家族成员的mRNA编码，主要形式为Homer-1b，这与这些细胞的免疫化学分析一致。免疫化学分析无法检测Homer-1a。为了检测Homer-1a的功能，我们转染了编码mglur1 α或Homer-1a的cDNA，或同时转染了这两种cDNA。当细胞与这两种蛋白的cDNA共转染时，免疫荧光染色和细胞表面分子的生物素化显示，与单独转染mGluR1alpha cDNA的细胞相比，细胞表面存在的受体数量显著增加。这一发现与双重转染细胞用激动剂处理后肌醇磷酸产生的同时增加是一致的。两种蛋白的细胞内免疫染色显示它们是共定位的，当它们共表达时，它们会重新分布到一个大的囊泡室中。
Homer-1a is a 30 kDa protein that forms part of a family of conserved Homer-related proteins that interact with the C-termini of the metabotropic glutamate receptors mGluR1alpha and mGluR5a. Analysis of HEK-293 cells by PCR showed that they contained mRNA coding for members of the Homer family with the predominant form being Homer-1b, which is consistent with the immunochemical analysis of these cells. Homer-1a could not be detected by immunochemical analysis. To examine the function of Homer-1a, HEK-293 cells were transfected with cDNA encoding mGluR1alpha or Homer-1a or co-transfected with both cDNAs. When cells were co-transfected with the cDNAs for both proteins, immunofluorescent staining and biotinylation of cell surface molecules revealed a significant increase in the amount of receptor present at the cell surface in contrast to cells transfected with mGluR1alpha cDNA alone. This finding was consistent with a concomitant increase in the production of inositol phosphates after treatment of the doubly transfected cells with agonist. Intracellular immunostaining for both proteins revealed that they were co-localized and underwent a redistribution into a large vesicular compartment when they were co-expressed.