Functional Analysis of Activins During Development

描述(申请人提供)：转化生长因子β(TGFbeta)超家族是哺乳动物中最大的分泌蛋白家族。该家族包括激活素、抑制素、转化生长因子β、骨形态发生蛋白和生长分化因子。这些配体通过跨膜型I型和II型丝氨酸/苏氨酸激酶受体的寡聚复合体传递信号。配体诱导的这些受体的异二聚化导致受体调节的SMAD蛋白的磷酸化，这些蛋白与共同的Smad4蛋白一起转移到细胞核并调节基因的表达。这些信号通路突变的小鼠和人类的特征揭示了这个家族在发育和生理过程中发挥作用的多样性。通过这笔赠款的支持，我的实验室已经培育出并分析了激活素亚单位、激活素结合蛋白(卵泡抑素)、激活素受体II型、下游受体结合蛋白(FKBP 12)和SMADS突变的小鼠。我们最近已经证明，卵泡抑素颗粒细胞切除的小鼠是女性卵巢早衰的模型。这些基因敲除小鼠在体内定义基因功能的效用是无与伦比的，这些强大的遗传模型对于研究发育和生殖是不可或缺的。R01更新的总体假设是，我们将能够使用现有的和新创建的卵巢特异性基因敲除小鼠模型来剖析卵巢中的TGFbeta信号通路。这些研究将使我们能够将配体、受体和下游的SMAD蛋白放入单细胞类型(即卵巢颗粒细胞)的生物途径中。这些研究的具体目的如下：1)建立转基因模型以明确激活素在卵巢内的作用；2)剖析卵巢中激活素受体II、BMP受体II和BMP受体I的信号通路；3)研究SMAD下游蛋白在卵巢生理中的相互关系。这些转基因小鼠的产生和鉴定将定义卵巢中必不可少的和相互作用的TGFa超家族信号成分和通路，并将继续成为人类生殖疾病(包括不孕症、卵巢早衰、多囊卵巢综合征和卵巢癌)的重要模型。

DESCRIPTION (provided by applicant): The transforming growth factor beta (TGFbeta) superfamily is the largest family of secreted proteins in mammals. This family includes the activins, inhibins, TGFbetas, bone morphogenetic proteins (BMPs), and growth differentiation factors (GDFs). These ligands signal through an oligomeric complex of transmembrane type I and type II serine/threonine kinase receptors. Ligand-induced heterodimerization of these receptors leads to phosphorylation of receptor-regulated SMAD proteins, which translocate to the nucleus with the common SMAD4 protein and regulate gene expression. The characterization of mice and humans with mutations in these signaling pathways has revealed the diversity of developmental and physiological processes in which this family functions. Through the support of this grant, my laboratory has generated and analyzed mice with mutations in activin subunits, an activin binding protein (follistatin), activin receptor type II, a downstream receptor binding protein (FKBP 12), and SMADS. We have recently shown that mice with granulosa cell ablation of follistatin are a model for premature ovarian failure in women. The utility of these knockout mice in defining gene function in vivo is unparalleled, and these powerful genetic models have been indispensable for investigating development and reproduction. The overall hypothesis of this R01 renewal is that we will be able to dissect the TGFbeta signaling pathways in the ovary using available and newly-created ovary-specific knockout mouse models. These studies will allow us to place ligands, receptors, and downstream SMAD proteins into biological pathways in a single cell type (i.e., The granulosa cells of the ovary). The Specific Aims of the proposed studies are as follows: 1) Produce transgenic models to define the intraovarian roles of activins; 2) Dissect the activin receptor type II, BMP receptor type II, and BMP receptor type I signaling pathways in the ovary; and 3) Study the interrelationships of the downstream SMAD proteins in ovarian physiology. Generation and characterization of these transgenic mice will define essential and interacting TGFa superfamily signaling components and pathways in the ovary and will continue to be important models for human reproductive diseases including infertility, premature ovarian failure, polycystic ovary syndrome, and ovarian cancer.