缺陷的 C1GALT1C1 导致 TNPS
中文名称
通路描述
糖蛋白-N-乙酰半乳糖胺 3-β-半乳糖基转移酶 1（C1GALT1；MIM:610555）介导从 UDP-半乳糖转移到单 O-连接 GalNAc 残基（Tn 抗原）的半乳糖（Gal），形成糖蛋白上的 Core 1 结构。C1GALT1 在与分子伴侣 C1GALT1C1（也称为 COSMC；MIM:300611）复合物时活性最高，后者协助 C1GALT1 的折叠和/或稳定性。C1GALT1C1 的缺陷导致体细胞 Tn 聚糖聚积综合征（TNPS；MIM:300622），其特征是 Tn 抗原暴露后，由天然存在的抗 Tn 抗体引起的红细胞聚糖聚积。C1GALT1C1 的缺陷使 C1GALT1 失活，导致不完全糖基化的 Tn 抗原积累。Tn 抗原是肿瘤相关的，在大多数人类癌变中均存在，并在外周组织或血液中通常不表达（Crew et al. 2008, Ju et al. 2014）。C1GALT1 和 C1GALT1C1 属于 CAZy 家族 GT31（www.cazy.org）。
英文描述
Defective C1GALT1C1 causes TNPS Glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1; MIM:610555) mediates the transfer of Galactose (Gal) from UDP-galactose to single O-linked GalNAc residues (Tn antigens) to form Core 1 structures on glycoproteins. C1GALT1 is active when in complex with the molecular chaperone C1GALT1C1 (aka COSMC; MIM:300611) which assists the folding and/or stability of C1GALT1. Defects in C1GALT1C1 causes somatic Tn polyagglutination syndrome (TNPS; MIM:300622), characterised by the polyagglutination of erythrocytes by naturally occurring anti-Tn antibodies following exposure of the Tn antigen on their surface. Defects in C1GALT1C1 render C1GALT1 inactive and results in the accumulation of the incompletely glycosylated Tn antigen. The Tn antigen is tumour-associated, found in a majority of human carcinomas, and is not normally expressed in peripheral tissues or blood cells (Crew et al. 2008, Ju et al. 2014). C1GALT1 and C1GALT1C1 belong to the CAZy family GT31 (www.cazy.org).
所含基因
7 个基因