STRUCTURE AND FUNCTION OF THE I REGION GENES

主要组织相容性复合体II类抗原是其 主要功能是将抗原递呈给T辅助细胞。这个 在适当的时间，在适当的细胞中表达这些蛋白质， 对免疫系统的有效运作至关重要。我们的 主要的兴趣是研究编码MHC II类的基因是如何 抗原既以细胞特有的方式调节，又受细胞因子的调节。 这些基因调控的中心是转录的组装 位于基因上游的顺式作用元件的影响因素。按顺序 为了更好地了解这些因素是如何发挥作用的，我们建议确定和 MHC-II类基因涉及的转录因子的特征 表情。 最初的目标是确定与DNA结合蛋白结合的 MHC II类基因的上游区域，I-Abeta。因为太低了 大量的这些蛋白质，我们设计了几种方法 克隆这些DNA结合因子的基因。一旦这些基因被 克隆后，我们将能够产生足够数量的蛋白质 对蛋白质进行更详细的表征。基本上，我们希望 要知道这些DNA结合蛋白是否反映了转录活性 I-Aβ基因。可能要调查的变化包括 基因的剪接模式和细胞的磷酸化状态 蛋白质。任何发现的变化都将测试其对 抄写。 很可能存在与DNA结合相关的蛋白质 通过蛋白质-蛋白质相互作用的蛋白质。我们的第二个目标将是 来鉴定这些类型的蛋白质。存在或不存在 表达MHC-II类基因的细胞中的特定蛋白质可能提供新的 关于II类基因如何调控的想法。如果我们看到一种蛋白质 只在表达第二类基因的细胞中表达，这种蛋白将被 是进一步定性的极佳人选。 我们还建议研究MHC-II类基因在患者中的表达 MHC-II类分子表达不足。有可能是因为 缺乏症的基础是转录因子。我们将开始这项工作 通过检测我们拥有的DNA结合蛋白的基因进行研究 具有任何缺陷的特征。One激活结构域中的突变 这些蛋白质中的一种可能足以彻底改变 第二类基因。 最后，我们将在转基因小鼠身上测试各种I-Abeta结构。这个 这些实验的设计是为了识别新的顺式作用元件，这些元件可能 对于发育调节的I-Abeta的表达是重要的 吉恩。

The major histocompatibility complex class II antigens have as one of their primary functions the presentation of antigen to T helper cells. The expression of these proteins in the proper cells, and at the proper time, is critical for the effective functioning of the immune system. Our primary interest is to examine how the genes coding for the MHC class II antigens are regulated in both a cell specific manner and by cytokines. Central to the regulation of these genes is the assembly of transcription factors on the cis-acting elements located upstream of the genes. In order to better understand how these factors work, we propose to identify and characterize the transcription factors involved in MHC class II gene expression. The initial goal will be to identify DNA binding proteins that bind to the upstream region of the MHC class II gene, I-Abeta. Because of the low quantities of these proteins in cells, we have designed several approaches to clone the genes for these DNA binding factors. Once the genes have been cloned, we will be able to generate sufficient quantities of protein for a more detailed characterization of the proteins. Basically, we would like to know if these DNA binding proteins reflect the transcriptional activity of the I-Abeta gene. Possible changes to be investigated include the splicing pattern of the genes and the phosphorylation status of the proteins. Any change found will be tested for its influence on transcription. It is likely that there are proteins that associate with the DNA binding proteins via protein-protein interactions. A second goal of ours will be to identify these types of proteins. The presence or absence of a particular protein in cells that express MHC class II genes may provide new ideas on how the class II genes are regulated. If we see a protein expressed only in cells that express class II genes, this protein will be an excellent candidate for further characterization. We also propose to study the expression of MHC class II genes in patients with a deficiency in MHC class II expression. It is possible that the deficiency has its basis in a transcription factor. We will begin this study by examining the genes for the DNA binding proteins we have characterized for any defects. A mutation in the activation domain of one of these proteins may be sufficient to alter drastically the expression of the class II gene. Finally, we will test various I-Abeta constructs in transgenic mice. The design of these experiments is to identify new cis-acting elements that may be important for the developmentally regulated expression of the I-Abeta gene.