TRG - T cell receptor gamma locus Gene

中文名称：T 细胞受体 γ 位点

种属: Homo sapiens

同用名: TCRG; TRG@

关于 TRG

功能概要

细胞受体识别已被加工成小肽并与抗原呈递细胞 (APC) 表面的主要组织相容性复合体 (MHC) 分子结合的外来抗原。每个 T 细胞受体都是一个二聚体，由一条α链和一条β链或一条δ链和一条γ链组成。在单个细胞中，T 细胞受体基因座以 delta、gamma、beta 和 alpha 的顺序重新排列和表达。如果 delta 和 gamma 重排都产生功能链，则细胞表达 delta 和 gamma。如果不是，细胞会继续重新排列 beta 和 alpha 位点。该区域代表 T 细胞受体 γ 位点的种系组织。伽玛轨迹包括 V (可变) 、J (连接) 和 C (恒定) 片段。在 T 细胞发育过程中，γ 链是通过 DNA 水平的重组事件合成的，将 V 区段与 J 区段连接起来； C 段后来通过在 RNA 水平上的剪接连接。许多不同的 V 区段与几个 J 区段的重组提供了广泛的抗原识别。额外的多样性是通过连接多样性获得的，连接多样性是由末端脱氧核苷酸转移酶随机添加核苷酸引起的。已知 γ 基因座的几个 V 区段不能编码蛋白质，被认为是假基因。在来自 T 细胞白血病和共济失调性毛细血管扩张症患者的 T 细胞中观察到 γ 基因座的体细胞重排。[RefSeq 提供，2008 年 7 月]

T cell receptors recognize foreign antigens which have been processed as small Peptides and bound to major histocompatibility complex (MHC) molecules at the surface of antigen presenting cells (APC). Each T cell receptor is a dimer consisting of one alpha and one beta chain or one delta and one gamma chain. In a single cell, the T cell receptor loci are rearranged and expressed in the order delta, gamma, beta, and alpha. If both delta and gamma rearrangements produce functional chains, the cell expresses delta and gamma. If not, the cell proceeds to rearrange the beta and alpha loci. This region represents the germline organization of the T cell receptor gamma locus. The gamma locus includes V (variable), J (joining), and C (constant) segments. During T cell development, the gamma chain is synthesized by a recombination event at the DNA level joining a V segment with a J segment; the C segment is later joined by splicing at the RNA level. Recombination of many different V segments with several J segments provides a wide range of antigen recognition. Additional diversity is attained by junctional diversity, resulting from the random addition of nucleotides by terminal deoxynucleotidyltransferase. Several V segments of the gamma locus are known to be incapable of encoding a protein and are considered pseudogenes. Somatic rearrangement of the gamma locus has been observed in T cells derived from patients with T cell leukemia and ataxia telangiectasia. [provided by RefSeq, Jul 2008]