Reaction: POMK 6-phosphorylates Mannose in GalNAc-GlcNAc-Man-DAG1
- in pathway: O-linked glycosylation
Three enzymes are involved in the biosynthesis of a phosphorylated O-mannosyl trisaccharide structure (N-acetylgalactosamine-beta-1,3-N-acetylglucosamine-beta-1,4-(phosphate-6-)mannose) present in alpha-dystroglycan (DAG1), which is required for binding laminin G-like domain-containing extracellular proteins with high affinity. Defects in any of these enzymes can lead to congenital muscular dystrophy.
Once the mannosyl residue attached to DAG1 has had GlcNAc and GalNAc added to it by POMGNT2 and B3GALNT2 respectively, protein O-mannose kinase (POMK, SGK196) can phosphorylate position 6 of the mannosyl residue (Yoshida-Moriguchi et al. 2013). Defects in POMK can cause muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A12 (MDDGA12), a congenital muscular dystrophy that disrupts normal muscle development leading to locomotor dysfuction (Di Costanzo et al. 2014).
Once the mannosyl residue attached to DAG1 has had GlcNAc and GalNAc added to it by POMGNT2 and B3GALNT2 respectively, protein O-mannose kinase (POMK, SGK196) can phosphorylate position 6 of the mannosyl residue (Yoshida-Moriguchi et al. 2013). Defects in POMK can cause muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A12 (MDDGA12), a congenital muscular dystrophy that disrupts normal muscle development leading to locomotor dysfuction (Di Costanzo et al. 2014).
Reaction - small molecule participants:
ADP [endoplasmic reticulum lumen]
ATP [endoplasmic reticulum lumen]
Reactome.org reaction link: R-HSA-8931653
======
Reaction input - small molecules:
ATP(4-)
Reaction output - small molecules:
ADP(3-)
Reactome.org link: R-HSA-8931653