缺陷的 POMT2 导致 MDDGA2、MDDGB2 和 MDDGC2
中文名称
通路描述
蛋白 O-甘露糖转移酶 1 和 2（POMT1 和 POMT2；CAZy 家族 GT39）的共表达对于酶活性是必需的，即介导向蛋白质如α-糖蛋白（DAG1；MIM:128239）的羟基上的甘露糖残基转移。DAG1是一种细胞表面蛋白，在肌肉、脑和周围神经的外基质组装中发挥重要作用，通过将基底膜与细胞骨架蛋白连接起来。POMT2（MIM:607439）的缺陷导致DAG1糖基化缺陷，可引起严重先天性肌营养不良-糖蛋白病，从严重的类型A（MDDGA2，伴有脑和眼异常；MIM:613150），到较轻的类型B（MDDGB2，先天性伴有智力障碍；MIM:613156）再到较轻的类型C（MDDGC2，肢体带型；MIM:603158）（Bertini et al. 2011, Wells 2013）。
英文描述
Defective POMT2 causes MDDGA2, MDDGB2 and MDDGC2 Co-expression of both protein O-mannosyl-transferases 1 and 2 (POMT1 and POMT2; CAZy family GT39) is necessary for enzyme activity, that is mediating the transfer of mannosyl residues to the hydroxyl group of serine or threonine residues of proteins such as alpha-dystroglycan (DAG1; MIM:128239). DAG1 is a cell surface protein that plays an important role in the assembly of the extracellular matrix in muscle, brain, and peripheral nerves by linking the basal lamina to cytoskeletal proteins. Defects in POMT2 (MIM:607439) results in defective glycosylation of DAG1 and can cause severe congenital muscular dystrophy dystroglycanopathies ranging from a severe type A, MDDGA2 (brain and eye abnormalities; MIM:613150), through a less severe type B, MDDGB2 (congenital form with mental retardation; MIM:613156) to a milder type C, MDDGC2 (limb girdle form; MIM:603158) (Bertini et al. 2011, Wells 2013).
所含基因
2 个基因