STRUCTURE AND FUNCTION OF NON BASEMENT MEMBRANE LAMININS

最近发现了一条新的层粘连蛋白亚单位链--Gamma3。生化 对含层粘连蛋白的Gamma3的研究表明，Gamma3可以与AT 最少的α2、α4、β1和β2亚单位链。GAMA3的组织分布 表明它存在于不含超微结构定义的基底的区域 膜。这些区域包括大脑基质和大脑顶端表面 纤毛上皮细胞。以下具体目标描述了拟议的 意图检验这一假设，即含有层粘连蛋白的Gamma3形成独特的 在这些非基底膜位置的基质，其功能是 稳定组装所需的细胞骨架安排和 纤毛的稳定化，并且还提供可膨胀的基质稳定化 中枢神经系统的结构。为了检验这一假设，提出了具体的目标： (1)详细描述Gamma3和其他精选的解剖分布 层粘连蛋白链，以及已知的基质大分子和受体 发育期间和成人的脑和纤毛上皮表面 (2)测定小鼠体内含层粘连蛋白的Gamma3的分子组成。 脑部和纤毛上皮表面。适当的化学量 层粘连蛋白将在细胞培养中产生并纯化。(3)潜在的相互作用 在空间和时间上共域的分子之间将被测试 在试管中。与潜在受体的结合将通过细胞结合研究来确定。 (4)通过同源重组产生Gamma3缺失小鼠， 表型具有特征性。我们将杂交Gamma3和Beta2杂合子 小鼠产生双KO。这些研究很可能会提供 为进一步研究新型细胞外基质奠定了基础。这也是可能的 这些研究将为研究糖尿病的病理生理学提供新的见解。 神经退行性疾病和不孕不育。

A novel laminin subunit chain, gamma3, has been recently identified. Biochemical studies of gamma3 containing laminins show that gamma3 can associate with at least alpha2, alpha4, beta1, and beta2 subunit chains. The tissue distribution of gamma3 shows it to be present in regions not containing ultrastructurally defined basement membranes. These regions include the brain matrix and the apical surface of ciliated epithelial cells. The following specific aims describe proposed intentions to test the hypothesis that gamma3 containing laminins form a unique matrix at these non-basement membrane sites, the function of which is to stabilize the cytoskeletal arrangements required for the assembly and stabilization of cilia, and to also provide a distensible matrix stabilizing the structure of the CNS. To test this hypothesis specific aims are proposed: (1) Carefully describe the anatomical distribution of gamma3 and other selected laminin chains, as well as of known matrix macromolecules and receptors in the brain and at ciliated epithelial surfaces during development and in the adult mouse; (2) Determine the molecular composition of gamma3 containing laminins in the brain and at ciliated epithelial surfaces. Chemical quantities of the appropriate laminins will be produced in cell culture and purified. (3) Potential interactions between molecules which colocalized spatially and temporally will be tested in vitro. Binding to potential receptors will be determined by cell binding studies. (4) A gamma3 null mouse will be generated by homologous recombination and the phenotype characterized. We will cross the gamma3 and beta2 heterozygous mice to produce the double KO. It is likely that these studies will provide the foundations for further study of a novel extracellular matrix. It is also possible that these studies will provide novel insights into the pathophysiology of neurodegenerative diseases and infertility.