MOLECULAR CONTROL OF LUTEAL FUNCTION BY PROLACTIN

催乳素(PRL)是一种脑下垂体前叶激素，调节多种 包括哺乳、免疫反应和生殖等过程。在……里面 卵巢促性腺激素释放激素会增加卵巢中蛋白质的合成。 黄体和维持孕酮的分泌。虽然催乳素刺激了 黄体中蛋白质的整体合成，它有相当的 对37-kD内少数特定蛋白的强烈抑制作用 射程。37kD在催乳素的促孕作用中起重要作用 黄体。该蛋白具有20α-羟基类固醇的活性 脱氢酶(20α-HSD)在心脏停滞中起关键作用。 怀孕和黄体溶解。这次调查的总体目标是 阐明PRL传递信息和抑制的机制 20α-HSD基因活性。 目的1.研究催乳素对小鼠卵巢癌细胞作用的时程和剂量效应。 20α-HSD基因表达。黄素化颗粒细胞培养最好 符合这些目的。这些细胞同时表达20α-HSD和PRL 受体基因。细胞将被不同浓度的 PRL.之后将对细胞进行Northern和Western分析 不同处理检测20α-HSD的mRNA和蛋白水平。 目的2.检测JAK2和Stat 91是否分别是该激酶 与催乳素信号转导相关的转录因子(S)。雅克 激酶和Stat 91已被证明与该信号有关 干扰素-α、γ和其他成员在细胞内的转导 细胞因子/促红细胞生成素家族。催乳素受体(PRL-R)也是 在这个家族中，它很有可能传递自己的信号 通过类似的途径。这些实验的目的将是： A)了解PRL是否通过黄体化的JAK2激酶传递其信号 细胞将在没有或存在催乳素的情况下培养。细胞裂解物 将与抗JAK2免疫共沉淀。 B)进一步研究PRL-R和JAK2之间的关系，细胞 从+/-PRL处理的细胞中获得的裂解物将被免疫沉淀 抗PRL-R或抗JAK2。 C)PRL受体和非受体酪氨酸的磷酸化 蛋白水解酶和其他细胞蛋白可以通过在 体内磷酸化。细胞将与催乳素和[伽马- ~(32)P]ATP，细胞裂解物将与PRL-R进行免疫沉淀 抗体、JAK2和Stat 91抗体及电泳法 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.