Component of the glycosylphosphatidylinositol-anchor (GPI-anchor) transamidase (GPI-T) complex that catalyzes the formation of the linkage between a proprotein and a GPI-anchor and participates in GPI anchored protein biosynthesis (PubMed:11483512, PubMed:12582175, PubMed:28327575, PubMed:34576938, PubMed:35165458, PubMed:35551457, PubMed:36970549, PubMed:37684232). May play a crucial role in GPI-T complex assembly in the luminal layer (PubMed:35165458, PubMed:35551457). Binds GPI-anchor (PubMed

Endoplasmic reticulum membrane

Multiple congenital anomalies-hypotonia-seizures syndrome 3

An autosomal recessive syndrome characterized by distinct facial features, intellectual disability, hypotonia and seizures, in combination with abnormal skeletal, endocrine, and ophthalmologic findings including impaired vision, as well as abnormal motility of the eyes.

Catalyzes the second step of glycosylphosphatidylinositol (GPI) biosynthesis, which is the de-N-acetylation of N-acetylglucosaminyl-phosphatidylinositol

Endoplasmic reticulum membrane

Coloboma, congenital heart disease, ichthyosiform dermatosis, impaired intellectual development, and ear anomalies syndrome

An extremely rare autosomal recessive multisystem disorder clinically characterized by colobomas, congenital heart defects, migratory ichthyosiform dermatosis, intellectual disability, and ear anomalies including conductive hearing loss. Other clinical features include distinctive facial features, abnormal growth, genitourinary abnormalities, seizures, and feeding difficulties.

Catalytic subunit of the ethanolamine phosphate transferase 2 complex that transfers an ethanolamine phosphate (EtNP) from a phosphatidylethanolamine (PE) to the 6-OH position of the second alpha-1,6-linked mannose of a 2-acyl-6-[6-phosphoethanolamine-alpha-D-mannosyl-(1->2)-alpha-D-mannosyl-(1->6)-2-phosphoethanolamine-alpha-D-mannosyl-(1->4)-alpha-D-glucosaminyl]-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol (also termed H7) intermediate to generate a 2-acyl-6-[6-phosphoethanolamine-

Endoplasmic reticulum membrane

Neurodevelopmental disorder with or without hypotonia, seizures, and cerebellar atrophy

An autosomal recessive disorder characterized by delayed psychomotor development, hypotonia, and early-onset seizures in most patients. Additional variable features are cerebellar atrophy, ataxia, and non-specific dysmorphic features. Some patients may have the Emm-null blood group phenotype.

Transfers the sialyl group (N-acetyl-alpha-neuraminyl or NeuAc) from CMP-NeuAc to the non-reducing terminal galactose (Gal) of glycosphingolipids forming gangliosides (important molecules involved in the regulation of multiple cellular processes, including cell proliferation and differentiation, apoptosis, embryogenesis, development, and oncogenesis) (PubMed:16934889, PubMed:9822625). Mainly involved in the biosynthesis of ganglioside GM3 but can also use different glycolipids as substrate accep

Golgi apparatus membrane

Salt and pepper developmental regression syndrome

A rare autosomal recessive disorder characterized by infantile onset of severe, recurrent and refractory seizures, failure to thrive, psychomotor delay, developmental stagnation, and cortical blindness. Deafness is observed in some patients. Affected individuals have patches of skin hypo- or hyperpigmentation on the trunk, face, and extremities.

Catalytic subunit of the ethanolamine phosphate transferase 3 complex that transfers an ethanolamine phosphate (EtNP) from a phosphatidylethanolamine (PE) to the 6-OH position of the third alpha-1,2-linked mannose of the a 2-acyl-6-[alpha-D-mannosyl-(1->2)-alpha-D-mannosyl-(1->6)-2-phosphoethanolamine-alpha-D-mannosyl-(1->4)-alpha-D-glucosaminyl]-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol (also termed H6) intermediate to generate a a 2-acyl-6-[6-phosphoethanolamine-alpha-D-mannosyl-

Endoplasmic reticulum membrane

Hyperphosphatasia with impaired intellectual development syndrome 2

An autosomal recessive form of intellectual disability characterized by facial dysmorphism, brachytelephalangy, and persistent elevated serum alkaline phosphatase (hyperphosphatasia). Some patients may have additional features, such as cardiac septal defects or seizures.

Catalytic subunit 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

Rough endoplasmic reticulum membrane

Paroxysmal nocturnal hemoglobinuria 1

A disorder characterized by hemolytic anemia with hemoglobinuria, thromboses in large vessels, and a deficiency in hematopoiesis. Red blood cell breakdown with release of hemoglobin into the urine is manifested most prominently by dark-colored urine in the morning.

Involved in the fatty acid remodeling steps of GPI-anchor maturation where the unsaturated acyl chain at sn-2 of inositol phosphate is replaced by a saturated stearoyl chain (PubMed:17021251, PubMed:24439110). May catalyze the first step of the fatty acid remodeling, by removing the unsaturated acyl chain at sn-2 of inositol phosphate, generating a lyso-GPI intermediate (Probable). The fatty acid remodeling steps is critical for the integration of GPI-APs into lipid rafts (By similarity)

Golgi apparatus membrane

Hyperphosphatasia with impaired intellectual development syndrome 4

An autosomal recessive neurologic disorder characterized by profound developmental delay, severe intellectual disability, no speech, psychomotor delay, postnatal microcephaly, and elevated serum alkaline phosphatase.

Acyltransferase that catalyzes the acyl transfer from an acyl-CoA at the 2-OH position of the inositol ring of a 6-(alpha-D-glucosaminyl)-1-(1,2-diacyl-sn-glycero-3-phospho)-1D-myo-inositol (glucosaminyl phosphatidylinositol, GlcN-PI) to generate a 2-acyl-6-alpha-D-glucosaminyl-1-(1,2-diacyl-sn-glycero-3-phospho)-1D-myo-inositol (glucosaminyl acyl phosphatidylinositol, GlcN-(acyl)PI) and participates in the fourth step of GPI-anchor biosynthesis (By similarity). Required for the transport of GPI

Endoplasmic reticulum membrane

Glycosylphosphatidylinositol biosynthesis defect 11

An autosomal recessive neurologic disorder characterized by developmental delay, intellectual disability, tonic seizures associated with hypsarrhythmia, dysmorphic facial features, and elevated serum alkaline phosphatase.

Catalytic subunit of the glycosylphosphatidylinositol-mannosyltransferase I complex which catalyzes the transfer of the first mannose, via an alpha-1,4 bond from a dolichol-phosphate-mannose (Dol-P-Man) to a 2-acyl-6-alpha-D-glucosaminyl-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol (glucosaminyl acyl phosphatidylinositol, GlcN-(acyl)PI) intermediate to generate 2-acyl-6-(alpha-D-mannosyl-(1->4)-alpha-D-glucosaminyl)-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol (also termed

Endoplasmic reticulum membrane

Glycosylphosphatidylinositol biosynthesis defect 1

An autosomal recessive disorder characterized by portal vein thrombosis and portal hypertension, absence seizures, macrocephaly, splenomegaly, cytopenias and early-onset cerebral infarctions.

Involved in the fatty acid remodeling steps of GPI-anchor maturation where the unsaturated acyl chain at sn-2 of inositol phosphate is replaced by a saturated stearoyl chain. May catalyze the second step of the fatty acid remodeling, by reacylating a lyso-GPI intermediate at sn-2 of inositol phosphate by a saturated chain (By similarity). The fatty acid remodeling steps is critical for the integration of GPI-APs into lipid rafts (PubMed:23561846)

Golgi apparatus membrane

Hyperphosphatasia with impaired intellectual development syndrome 3

An autosomal recessive disorder usually characterized by intellectual disability, hypotonia with very poor motor development, poor speech, and increased serum alkaline phosphatase.

Ethanolamine phosphate transferase that catalyzes an ethanolamine phosphate (EtNP) transfer from phosphatidylethanolamine (PE) to the 2-OH position of the first alpha-1,4-linked mannose of a 2-acyl-6-[alpha-D-mannosyl-(1->6)-alpha-D-mannosyl-(1->4)-alpha-D-glucosaminyl]-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol (also termed H3) intermediate to generate a 2-acyl-6-[alpha-D-mannosyl-(1->6)-2-phosphoethanolamine-alpha-D-mannosyl-(1->4)-alpha-D-glucosaminyl]-1-(1-radyl,2-acyl-sn-glycer

Endoplasmic reticulum membrane

Multiple congenital anomalies-hypotonia-seizures syndrome 1

An autosomal recessive disorder characterized by neonatal hypotonia, lack of psychomotor development, seizures, dysmorphic features, and variable congenital anomalies involving the cardiac, urinary, and gastrointestinal systems. Most affected individuals die before 3 years of age.

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:16162815). May act by regulating the catalytic subunit PIGA (PubMed:16162815)

Endoplasmic reticulum membrane

Hyperphosphatasia with impaired intellectual development syndrome 6

An autosomal recessive, multisystem disorder characterized by severe developmental delay, dysmorphism, seizures, cataracts, and early death in some patients.

Alpha-1,6-mannosyltransferase that catalyzes the transfer of the second mannose, via an alpha-1,6 bond, from a dolichol-phosphate-mannose (Dol-P-Man) to a 2-acyl-6-(alpha-D-mannosyl-(1->4)-alpha-D-glucosaminyl)-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol (also termed H2) intermediate to generate a 2-acyl-6-[alpha-D-mannosyl-(1->6)-alpha-D-mannosyl-(1->4)-alpha-D-glucosaminyl]-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol (also termed H3) and participates in the seventh step

Endoplasmic reticulum membrane

Hyperphosphatasia with impaired intellectual development syndrome 1

A severe syndrome characterized by elevated serum alkaline phosphatase, severe intellectual disability, seizures, hypotonia, facial dysmorphism, and hypoplastic terminal phalanges.