MOLECULAR CONTROL OF LUTEAL FUNCTION BY PROLACTIN

催乳素（PRL）是一种垂体前叶激素， 哺乳、免疫反应和生殖等过程的影响。 在 卵巢催乳素导致体内蛋白质合成增加 黄体和维持孕酮分泌。 尽管PRL刺激了 整体合成的蛋白质在黄体，它有一个相当 对37 kD内的少数特异性蛋白质有强烈的抑制作用 范围 37 kD在PRL的趋化作用中起重要作用， 黄体 该蛋白具有20 α-羟基类固醇活性， 脱氢酶（20 α-HSD）在终止 妊娠和黄体溶解。 本次调查的总体目标是 阐明PRL传递其信息并抑制 20 α-HSD基因活性。 目标1。 研究催乳素作用的时间过程和剂量反应， 20 α-HSD基因表达。 黄体化颗粒细胞培养最好 适合这些目的。 这些细胞同时表达20 α-HSD和PRL 受体基因 细胞将用不同浓度的 催乳素 将对细胞进行北方和西方分析， 不同的处理以检查20 α-HSD mRNA和蛋白质的水平。 目标二。 为了检测JAK 2和Stat 91是否分别是 和与PRL信号传导相关的转录因子。 JAK 激酶和Stat 91已被证明参与信号 干扰素-α、γ和其他成员的转导， 细胞因子/促红细胞生成素家族。 PRL受体（PRL-R）也是一种 很有可能它将信号传导到 通过类似的途径。 这些实验的目的是： a）为了发现PRL是否通过JAK 2激酶转导其信号， 细胞将在不存在或存在PRL的情况下培养。 细胞裂解物 将与抗JAK 2进行免疫沉淀。 B）为了进一步检查PRL-R和JAK 2之间的关系，细胞 将从+/- PRL处理的细胞获得的裂解物免疫沉淀 抗PRL-R或抗JAK 2抗体 c）PRL受体和非受体酪氨酸的磷酸化 激酶和其他细胞蛋白质的表达可以通过 体内磷酸化。 将细胞与PRL和[γ- 32 P]ATP，细胞裂解物将用PRL-R进行免疫沉淀 抗体、JAK 2和Stat 91抗体和电泳， 放射自显影

Prolactin (PRL) is an anterior pituitary hormone that regulates a variety of processes including lactation, immune response and reproduction. In the ovary PRL causes an increase in protein synthesis in the corpus luteum and sustains progesterone secretion. Although PRL stimulates the overall synthesis of proteins in the corpus luteum, it has a rather drastic inhibitory effect on few specific proteins within the 37-kD range. The 37 kD plays an important role in the tropic action of PRL in the corpus luteum. This protein with activity of 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) has a pivotal role in the termination of pregnancy and luteolysis. The overall goal of this investigation is to clarify the mechanism by which PRL transduces its message and inhibits the 20alpha-HSD gene activity. Aim 1. To examine the time course and dose response of PRL action on 20alpha-HSD gene expression. Luteinized granulosa cell culture will best suit these purposes. These cells express both 20alpha-HSD and the PRL receptor genes. Cells will be treated with different concentrations of PRL. Northern and Western analysis will be performed on the cells after different treatments to examine levels of 20alpha-HSD mRNA and protein. Aim 2. To examine whether JAK2 and Stat 91 are respectively the kinase and the transcriptional factor(s) associated with PRL signaling. JAK kinases and Stat 91 have been shown to be involved in the signal transduction of interferon-alpha, gamma and other members in the cytokine/erythropoietin family. PRL receptor (PRL-R) is also a member of this family, it is quite possible that it transduces its signal through similar pathway. The aims of these experiments will be: a) To find if PRL transduces its signal through JAK2 kinase, luteinized cells will be cultured in the absence or presence of PRL. Cell lysates will be immunoprecipitated with anti-JAK2. b) To further examine the relationship between PRL-R and JAK2, cell lysates obtained from cells treated +/- PRL will be immunoprecipitated with either anti-PRL-R or anti-JAK2. c) Phosphorylation of the PRL receptor and the non-receptor tyrosine kinases and other cellular proteins can be further demonstrated by in vivo phosphorylation. Cells will be incubated with PRL and [gamma- 32P]ATP, cell lysates will be subjected to immunoprecipitation with PRL-R antibody, JAK2 and Stat 91 antibodies and electrophoresis and autoradiography.