Struktur und Funktion von SMOC-1 und SMOC-2, zwei neuen modulären, calciumbindenden und Basalmembran-assoziierten Proteinen (Structure and funcation of SMOC-1 und SMOC-2, two novel modular calcium-binding proteins associated with basement membranes)

我们分离到了两个新的基因SMOC-1和SMOC-2。它们编码含有钙结合结构域的分泌模块蛋白，因此与BM-40蛋白家族同源。尽管如此，它们的领域构成是独一无二的。RT-PCR数据显示其在许多组织中广泛表达。针对重组人SMOC-1的抗血清的初步免疫荧光研究表明，该蛋白在基底膜上定位。我们首先想分析发育期间和成年小鼠中SMOC-1和-2的表达，鉴定表达这些蛋白的细胞类型，并通过电子显微镜研究它们的定位。重组SMOC-1和-2将在生物物理研究中用于鉴定基底膜上的结合伙伴。这些相互作用的相关性将通过组织共定位的演示来验证。负责结合活动的结构域将被识别，并绘制结合表位。基于这些结果，将选择相关的细胞和器官培养系统，并用于分析细胞环境中的功能。将尝试特定领域片段的结晶，以促进未来三维结构的确定。这些基因将被定位，为生产缺乏SMOC-1和-2的小鼠做准备。

We have isolated two novel genes SMOC-1 and SMOC-2. They encode secreted modular proteins that contain a calcium-binding domain and are thus homologous to the BM-40 protein family. Nonetheless their domain composition is unique. RT-PCR data indicate a widespread expression in many tissues. Preliminary immunofluorescence studies with an antiserum directed against recombinant human SMOC-1 demonstrate a basement membrane localisation of the protein. We first want to analyse the expression of SMOC-1 and -2 during development and in adult mice, identify the cell types that express the proteins and investigate their localisation by electron microscopy. Recombinant SMOC-1 and -2 will be used to identify their binding partner(s) in basement membranes in biophysical studies. The relevance of these interactions will be verified by the demonstration of colocalisation in tissues. Domains responsible for binding activities will be identified and binding epitopes mapped. Based on these results relevant cell and organ culture systems will be selected and used to analyse the function in a cellular context. Crystallisation of the domain-specific fragments will be attempted to facilitate the future determination of three-dimensional structures. The genes will be mapped to prepare for the production of mice deficient in SMOC-1 and -2.