Cloning, expression, and localization of MNAR/PELP1 in rodent brain:: Colocalization in estrogen receptor-α- but not in gonadotropin-releasing hormone-positive neurons
Cloning, expression, and localization of MNAR/PELP1 in rodent brain:: Colocalization in estrogen receptor-α- but not in gonadotropin-releasing hormone-positive neurons
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DOI：
10.1210/en.2005-0276
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发表时间：
2005-12-01
期刊：
影响因子：
4.8
通讯作者：
Brann, DW
中科院分区：
文献类型：
--
作者：
Khan, MM;Hadman, M;Brann, DW
Mnar/PELP1是最近在人类中发现的一种支架蛋白，它通过促进与Src/Erk激活级联的连锁/串扰来调节雌激素受体的非基因组活性。我们报道了大鼠Mnar/PELP1的克隆，并提供了有关其在雌性大鼠脑内的分布及其与雌激素受体-α(ER-α)和促性腺激素释放激素(GnRH)共定位的新信息。基于聚合酶链式反应的大鼠下丘脑Mnar/PELP1基因的转录产物全长约3.4kb，与已发表的人Mnar/PELP1序列有86%的同源性，并保留了其一级结构中所有关键的结合基序(PxxP、LxxL1和谷氨酸簇)，这些基序对其与Src和类固醇受体的相互作用至关重要。RT-PCR显示MnAR/PELP1转录本在脑的许多区域都有表达，免疫组织化学研究显示在下丘脑、大脑皮层、海马体、杏仁核和小脑等区域有强烈的MnAR/PELP1免疫反应(Mnar/PELP1-ir)。Mnar/PELP1-ir主要定位于胞核，但也可见少量胞浆和质膜相关染色。Mnar/PELP1-ir也主要是神经元，尽管在特定的脑区观察到一些胶质细胞的定位。共定位研究表明，脑内大多数ER-α阳性细胞共定位于Mnar/PELP1-ir。相反，Mnar/PELP1-ir在GnRH神经元中很少共定位。总之，本研究提供了证据表明，Mnar/PELP1在已知的类固醇作用靶点的大鼠大脑的关键神经组织中表达，其表达主要是神经元，并且Mnar/PELP1-ir强烈共存于ER-α，而不是GnRH神经元。
MNAR/PELP1 is a recently identified scaffold protein in the human that modulates the nongenomic activity of estrogen receptors by facilitating linkage/cross talk with the Src/Erk activation cascade. We report herein the cloning of rat MNAR/PELP1 and provide new information concerning its distribution in the female rat brain and its degree of colocalization with estrogen receptor-alpha (ER-alpha) and GnRH. PCR-based cloning of MNAR/PELP1 from rat hypothalamus yielded a transcript of approximately 3.4 kb, which shows 86% homology to the published human MNAR/PELP1 sequence and retained all the key binding motifs (PXXP, LXXLL, and glutamic acid clusters) in its primary structure that are known to be critical for its interaction with Src and steroid receptors. RT-PCR revealed that the MNAR/PELP1 transcript is expressed in many regions of the brain, and immunohistochemistry studies showed intense MNAR/PELP1 immunoreactivity (MNAR/PELP1-ir) in areas such as the hypothalamus, cerebral cortex, hippocampus, amygdala, and cerebellum. MNAR/PELP1-ir principally localized in the nucleus, but some cytoplasmic and plasma membrane-associated staining was also observed. MNAR/PELP1-ir was also primarily neuronal, although some localization in glia cells was observed in select brain regions. Colocalization studies revealed that a majority of ER-alpha-positive cells in the brain colocalized MNAR/PELP1-ir. In contrast, MNAR/PELP1-ir rarely colocalized in GnRH neurons. In conclusion, the current study provides evidence that MNAR/PELP1 is expressed in key neural tissues of the rat brain that are known targets of steroid action, that its expression is primarily neuronal, and that MNAR/PELP1-ir is strongly colocalized in ER-alpha, but not GnRH neurons in the rodent brain.