STRUCTURE AND FUNCTION OF THE MEN1 GENE AND ITS PROTEIN PRODUCT, MENIN

MEN1基因是一种肿瘤抑制基因 由NIH合作小组的位置克隆识别 包括MDB的成员。该基因的种系突变是 发现于受影响的MEN1家系受试者和体细胞 在零星的内分泌中发现了该基因的突变 和其他肿瘤。该基因编码一个610残基蛋白，称为 与其他已知蛋白质没有同源性和没有 明显的功能图案。我们已经开始了一系列的研究 旨在定义结构，功能，亚细胞定位， 和薄荷素的表达范围。我们已经产生了一系列 已被证明在免疫印迹中有用的多克隆多肽抗血清 和免疫沉淀研究。此外，这些抗体 检测重组形式的薄荷素的表达用于 结构和生化分析。编码薄荷素的cDNA具有 在293细胞中瞬时转染，并用于 亚细胞分离后监测其表达。这些研究 与我们的GFP标记脑膜素研究相结合 NHGRI的合作者已经表明，薄荷素主要是 定位于细胞核。一种果蝇细胞表达系统 已经建立了稳定的薄荷素转染体。这使我们能够 用免疫亲和技术从培养细胞中纯化薄荷素 层析法。精制的薄荷脑将用于详细的 生化和结构研究旨在阐明正常 该抑癌基因产物的功能，并阐明如何 基因突变会导致功能丧失。

The MEN1 gene is a tumor suppressor gene identified by positional cloning by an NIH collaborative group including members of MDB. Germline mutations in the gene are found in affected subjects of MEN1 kindreds, and somatic mutations in the gene have been identified in sporadic endocrine and other tumors. The gene encodes a 610 residue protein termed menin without homology to other known proteins and without obvious functional motifs. We have initiated a series of studies aimed at defining the structure, function, subcellular localization, and range of expression of menin. We have generated a series of polyclonal peptide antisera that have proved useful in immunoblot and immunoprecipitation studies. Furthermore,these antibodies detect the expression of recombinant forms of menin to be used for structural and biochemical analyses.The cDNA encoding menin has been transiently transfected in 293 cells and antibodies used to monitor its expression after subcellular fractionation. These studies in conjunction with studies of GFP-tagged menin conducted by our collaborators in NHGRI have shown that menin is primarily localized to the nucleus. A drosophila cell expression system has been established with menin stably transfected. This has enabled us to purify menin from cultured cells using immunoaffinity chromatography. Purified menin will be used for detailed biochemical and structural studies aimed at elucidating the normal function of this tumor suppressor gene product, and clarifying how mutations in the gene cause loss of function.