Protein O-mannose kinase that specifically mediates phosphorylation at the 6-position of an O-mannose of the trisaccharide (N-acetylgalactosamine (GalNAc)-beta-1,3-N-acetylglucosamine (GlcNAc)-beta-1,4-mannose) to generate phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-1,3-N-acetylglucosamine-beta-1,4-(phosphate-6-)mannose). Phosphorylated O-mannosyl trisaccharide is a carbohydrate structure present in alpha-dystroglycan (DAG1), which is required for binding laminin G-like d

Endoplasmic reticulum membrane

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A12

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

Transfers mannosyl residues to the hydroxyl group of serine or threonine residues. Coexpression of both POMT1 and POMT2 is necessary for enzyme activity, expression of either POMT1 or POMT2 alone is insufficient (PubMed:14699049, PubMed:28512129). Essentially dedicated to O-mannosylation of alpha-DAG1 and few other proteins but not of cadherins and protocaherins (PubMed:28512129)

Endoplasmic reticulum membrane

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A2

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

Cytidylyltransferase required for protein O-linked mannosylation (PubMed:22522420, PubMed:22522421, PubMed:26687144, PubMed:26923585, PubMed:27130732, PubMed:27601598). Catalyzes the formation of CDP-ribitol nucleotide sugar from D-ribitol 5-phosphate (PubMed:26687144, PubMed:26923585, PubMed:27130732). CDP-ribitol is a substrate of FKTN during the biosynthesis of the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3-N-acetylglucosamine-beta-4-(phosphate-6-)mannose), a carboh

Cytoplasm, cytosol

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A7

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

Beta-1,4-glucuronyltransferase involved in O-mannosylation of alpha-dystroglycan (DAG1) (PubMed:19587235, PubMed:23359570, PubMed:25279697, PubMed:25279699). Transfers a glucuronic acid (GlcA) residue onto a xylose (Xyl) acceptor to produce the glucuronyl-beta-1,4-xylose-beta disaccharide primer, which is further elongated by LARGE1, during synthesis of phosphorylated O-mannosyl glycan (PubMed:25279697, PubMed:25279699). Phosphorylated O-mannosyl glycan is a carbohydrate structure present in alp

Golgi apparatus membrane

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A13

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

Acts as a UDP-D-xylose:ribitol-5-phosphate beta1,4-xylosyltransferase, which catalyzes the transfer of UDP-D-xylose to ribitol 5-phosphate (Rbo5P) to form the Xylbeta1-4Rbo5P linkage on O-mannosyl glycan (Probable) (PubMed:27733679, PubMed:29477842). Participates in the biosynthesis of the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3-N-acetylglucosamine-beta-4-(phosphate-6-)mannose), a carbohydrate structure present in alpha-dystroglycan (DAG1), which is required for bin

Golgi apparatus membrane

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A10

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

Catalytic subunit of the GMPPA-GMPPB mannose-1-phosphate guanylyltransferase complex (PubMed:33986552). Catalyzes the formation of GDP-mannose, an essential precursor of glycan moieties of glycoproteins and glycolipids (PubMed:33986552). Can catalyze the reverse reaction in vitro (PubMed:33986552). Together with GMPPA regulates GDP-alpha-D-mannose levels (PubMed:33986552)

Cytoplasm

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A14

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with brain anomalies, eye malformations, and profound intellectual disability. The disorder includes a severe form designated as Walker-Warburg syndrome and a less severe phenotype known as muscle-eye-brain disease. MDDGA14 features include increased muscle tone, microcephaly, cleft palate, feeding difficulties, severe muscle weakness, sensorineural hearing loss, cerebellar hypoplasia, ataxia, and retinal dysfunction.

Type IV collagen is the major structural component of glomerular basement membranes (GBM), forming a 'chicken-wire' meshwork together with laminins, proteoglycans and entactin/nidogen Arresten, comprising the C-terminal NC1 domain, inhibits angiogenesis and tumor formation. The C-terminal half is found to possess the anti-angiogenic activity. Specifically inhibits endothelial cell proliferation, migration and tube formation

Secreted, extracellular space, extracellular matrix, basement membrane

Hereditary angiopathy with nephropathy aneurysms and muscle cramps

The clinical renal manifestations include hematuria and bilateral large cysts. Histologic analysis revealed complex basement membrane defects in kidney and skin. The systemic angiopathy appears to affect both small vessels and large arteries.

Regulates the biosynthesis of dolichol phosphate-mannose (PubMed:10835346). Regulatory subunit of the dolichol-phosphate mannose (DPM) synthase complex; essential for the ER localization and stable expression of DPM1 (PubMed:10835346). Part of the glycosylphosphatidylinositol-N-acetylglucosaminyltransferase (GPI-GnT) complex that catalyzes the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to phosphatidylinositol and participates in the first step of GPI biosynthesis (PubMed:161628

Endoplasmic reticulum membrane

Congenital disorder of glycosylation 1U

A form of congenital disorder of glycosylation, a multisystem disorder caused by a defect in glycoprotein biosynthesis and characterized by under-glycosylated serum glycoproteins. Congenital disorders of glycosylation result in a wide variety of clinical features, such as defects in the nervous system development, psychomotor retardation, dysmorphic features, hypotonia, coagulation disorders, and immunodeficiency. The broad spectrum of features reflects the critical role of N-glycoproteins during embryonic development, differentiation, and maintenance of cell functions. Some CDG1U patients have dystrophic changes seen on muscle biopsy and reduced O-mannosyl glycans on alpha-dystroglycan.

Beta-1,3-N-acetylgalactosaminyltransferase that synthesizes a unique carbohydrate structure, GalNAc-beta-1-3GlcNAc, on N- and O-glycans. Has no galactose nor galactosaminyl transferase activity toward any acceptor substrate. Involved in alpha-dystroglycan (DAG1) glycosylation: acts coordinately with GTDC2/POMGnT2 to synthesize a GalNAc-beta3-GlcNAc-beta-terminus at the 4-position of protein O-mannose in the biosynthesis of the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3

Golgi apparatus membraneEndoplasmic reticulum

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A11

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

Stabilizer subunit of the dolichol-phosphate mannose (DPM) synthase complex; tethers catalytic subunit DPM1 to the endoplasmic reticulum

Endoplasmic reticulum membrane

Muscular dystrophy-dystroglycanopathy congenital with impaired intellectual development B15

An autosomal recessive, congenital muscular disorder characterized by hyperCKemia, myopathic features observed on muscle biopsy, developmental delay, mildly impaired intellectual development with learning difficulties, epilepsy, and mild white matter abnormalities.

O-linked mannose beta-1,4-N-acetylglucosaminyltransferase that transfers UDP-N-acetyl-D-glucosamine to the 4-position of the mannose to generate N-acetyl-D-glucosamine-beta-1,4-O-D-mannosylprotein. Involved in the biosynthesis of the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3-N-acetylglucosamine-beta-4-(phosphate-6-)mannose), a carbohydrate structure present in alpha-dystroglycan (DAG1), which is required for binding laminin G-like domain-containing extracellular prote

Endoplasmic reticulum membrane

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A8

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

Transfers mannosyl residues to the hydroxyl group of serine or threonine residues. Coexpression of both POMT1 and POMT2 is necessary for enzyme activity, expression of either POMT1 or POMT2 alone is insufficient (PubMed:12369018, PubMed:14699049, PubMed:28512129). Essentially dedicated to O-mannosylation of alpha-DAG1 and few other proteins but not of cadherins and protocaherins (PubMed:28512129)

Endoplasmic reticulum membrane

Muscular dystrophy-dystroglycanopathy congenital with impaired intellectual development B1

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with intellectual disability and mild structural brain abnormalities.

Catalyzes the transfer of a ribitol 5-phosphate from CDP-L-ribitol to the ribitol 5-phosphate previously attached by FKTN/fukutin to the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3-N-acetylglucosamine-beta-4-(phosphate-6-)mannose), a carbohydrate structure present in alpha-dystroglycan (DAG1) (PubMed:26923585, PubMed:27194101, PubMed:29477842, PubMed:31949166). This constitutes the second step in the formation of the ribose 5-phosphate tandem repeat which links the phos

Golgi apparatus membraneSecretedCell membrane, sarcolemmaRough endoplasmic reticulumCytoplasm

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A5

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

The dystroglycan complex is involved in a number of signaling events and processes including laminin deposition and extracellular matrix assembly, acetylcholine receptor clustering, sarcolemmal stability, cell survival, peripheral nerve myelination, nodal structure, cell migration, epithelial polarization, and epithelium branching morphogenesis (By similarity). Required for the formation of photoreceptor ribbon synapses, and long-term maintenance of inhibitory synapses in cerebellar Purkinje cel

Secreted, extracellular spaceSecreted, extracellular space, extracellular matrix, basement membraneSynapseCell membraneCytoplasm, cytoskeletonNucleus, nucleoplasmCell membrane, sarcolemmaPostsynaptic cell membrane

Muscular dystrophy-dystroglycanopathy limb-girdle C9

An autosomal recessive muscular dystrophy showing onset in early childhood, and associated with intellectual disability without structural brain anomalies.

Participates in O-mannosyl glycosylation by catalyzing the addition of N-acetylglucosamine to O-linked mannose on glycoproteins (PubMed:11709191, PubMed:27493216, PubMed:28512129). Catalyzes the synthesis of the GlcNAc(beta1-2)Man(alpha1-)O-Ser/Thr moiety on alpha-dystroglycan and other O-mannosylated proteins, providing the necessary basis for the addition of further carbohydrate moieties (PubMed:11709191, PubMed:27493216). Is specific for alpha linked terminal mannose and does not have MGAT3,

Golgi apparatus membrane

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A3

An autosomal recessive disorder characterized by congenital muscular dystrophy, ocular abnormalities, cobblestone lissencephaly, and cerebellar and pontine hypoplasia. Patients present severe congenital myopia, congenital glaucoma, pallor of the optic disks, retinal hypoplasia, intellectual disability, hydrocephalus, abnormal electroencephalograms, generalized muscle weakness and myoclonic jerks. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.

Bifunctional glycosyltransferase with both alpha-1,3-xylosyltransferase and beta-1,3-glucuronyltransferase activities involved in the maturation of alpha-dystroglycan (DAG1) by glycosylation leading to DAG1 binding to laminin G-like domain-containing extracellular proteins with high affinity (PubMed:15661757, PubMed:15752776, PubMed:21987822, PubMed:22223806, PubMed:23125099, PubMed:25279697, PubMed:25279699). Elongates the glucuronyl-beta-1,4-xylose-beta disaccharide primer structure initiated

Golgi apparatus membrane

Muscular dystrophy-dystroglycanopathy congenital with impaired intellectual development B6

A congenital muscular dystrophy associated with profound intellectual disability, white matter changes and structural brain abnormalities. Skeletal muscle biopsies show reduced immunolabeling of alpha-dystroglycan.

Catalyzes the transfer of a ribitol-phosphate from CDP-ribitol to the distal N-acetylgalactosamine of the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3-N-acetylglucosamine-beta-4-(phosphate-6-)mannose), a carbohydrate structure present in alpha-dystroglycan (DAG1) (PubMed:26923585, PubMed:27194101, PubMed:29477842). This constitutes the first step in the formation of the ribitol 5-phosphate tandem repeat which links the phosphorylated O-mannosyl trisaccharide to the ligan

Golgi apparatus membraneCytoplasmNucleus

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A4

An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.