The nuclear, 75 kDa form of early growth response protein-1/nerve growth factor-induced A protein is primarily restricted to LH β-subunit-expressing cells in rat anterior pituitary
The nuclear, 75 kDa form of early growth response protein-1/nerve growth factor-induced A protein is primarily restricted to LH β-subunit-expressing cells in rat anterior pituitary
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DOI：
10.1530/eje.0.1430817
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发表时间：
2000-12-01
影响因子：
5.8
通讯作者：
Carter, D
中科院分区：
文献类型：
--
作者：
Knight, C;Slade, JP;Carter, D
目的：早期生长反应蛋白-1(Egr-1)/神经生长因子诱导的A(又称ZIF-268，KROX-24，TIS8，ZENK)是一种锌指转录因子，虽然在多种器官系统中表达，但仅在内分泌系统内的作用中起重要作用。黑麦利用免疫细胞化学和显微镜分析来观察Egr-1蛋白在细胞和亚细胞中的定位。方法：首先用免疫(Western)印迹法鉴定了一种商品化的Egr-1抗体检测到的垂体前叶蛋白。结果：Egr-1抗血清在垂体前叶提取液的Western印迹中检测到一条单一的、主要的(以核为主)75 kDa蛋白条带。免疫细胞化学证实75 kDa蛋白定位于大鼠和小鼠脑垂体前叶细胞的少数亚群。双重免疫细胞化学定位显示，Egr-1蛋白主要定位于黄体生成素β亚基表达细胞的细胞核。结论：Egr-1在细胞核内的定位与成年大鼠垂体前叶功能的转录调控有直接关系。此外，在促性腺激素基因表达的生理调控中也显示了选择性作用。
Objective: Early growth response protein-1 (Egr-1)/nerve growth factor-induced A (also known as Zif- 268, Krox-24, TIS8, ZENK) is a zinc-finger transcription factor which, although expressed in a range of organ systems, has been shown to be essential only in the maintenance of fertility through actions within the endocrine system, In the present study we have investigated the anatomical basis for actions of Egr-1 in the adult anterior pituitary gland.Design: Using female rats and mice as experimental models, rye have used immunocytochemical and microscopic analysis to make observations of the cellular and sub-cellular localization of Egr-1 protein.Methods: Immuno-(Western) blotting was first used to characterize the anterior pituitary proteins detected by a commercially available Egr-1 antibody. Subsequently the antibody was used both singly and in combination with an LH beta -subunit antibody for immunocytochemical localization studies in pituitary sections,Results: The Egr-1 antiserum detected a single, major (primarily nuclear) 75 kDa protein band in Western blots of anterior pituitary extracts. Nuclear localization was confirmed by immunocytochemistry, which also demonstrated that the 75 kDa protein is localized to a minority subpopulation of anterior pituitary cells in both rat and mouse. Dual immunocytochemical localization showed that the Egr-1 protein is primarily restricted to the nuclei of LH beta -subunit-expressing cells.Conclusions: Sub-cellular localization of Egr-1 to the nucleus is consistent with a direct role in transcriptional regulation of anterior pituitary function in the adult rat. Furthermore, a selective role in the physiological control of gonadotrophin gene expression is indicated.