Protein O-mannose kinase (POMK)

Protein O-mannose kinase (POMK) is an enzyme that catalyzes the phosphorylation of the C6-position of O-linked mannose on a specific trisaccharide (N-acetylgalactosamine-β1,3-N-acetylglucosamine-β1,4-mannose) present on α-dystroglycan, a critical protein in the linkage between the extracellular matrix and the cytoskeleton[2][6][1][3]. This posttranslational modification is essential for the proper binding of laminin and other extracellular matrix proteins, and thus for muscle integrity and certain aspects of brain development[2][1][3]. Genetic loss or mutations in POMK lead to a spectrum of severe congenital muscular dystrophies (notably Walker–Warburg syndrome), characterized by defective glycosylation of α-dystroglycan, disruption in ECM interaction, and secondary effects including abnormal neuronal migration and brain malformations[2][1]. POMK is classified within the kinase family, displaying a unique active site distinguishing it from classical protein kinases[4][5][3]. There are currently no known drugs targeting POMK, but its mutation status serves as a diagnostic and potentially prognostic biomarker in dystroglycanopathy subtypes[2]. The protein is sometimes referred to as a "pseudokinase" due to unconventional sequence and structural characteristics, though it possesses clearly demonstrated glycan kinase activity on its specific substrate[3][1].

Other names

SGK196SgK196protein kinase-like protein SgK196Sugen kinase 196FLJ23356MDDGA12MDDGC12