DPM1

Dolichol-phosphate mannose (Dol-P-Man) serves as a donor of mannosyl residues on the lumenal side of the endoplasmic reticulum (ER). Lack of Dol-P-Man results in defective surface expression of GPI-anchored proteins. Dol-P-Man is synthesized from GDP-mannose and dolichol-phosphate on the cytosolic side of the ER by the enzyme dolichyl-phosphate mannosyltransferase. Human DPM1 lacks a carboxy-terminal transmembrane domain and signal sequence and is regulated by DPM2. Mutations in this gene are associated with congenital disorder of glycosylation type Ie. Alternative splicing results in multiple transcript variants.

Full Name

dolichol-phosphate (beta-D) mannosyltransferase 1

Function

Transfers mannose from GDP-mannose to dolichol monophosphate to form dolichol phosphate mannose (Dol-P-Man) which is the mannosyl donor in pathways leading to N-glycosylation, glycosyl phosphatidylinositol membrane anchoring, and O-mannosylation of proteins; catalytic subunit of the dolichol-phosphate mannose (DPM) synthase complex.

Biological Process

Dolichol metabolic process Source: MGI
GDP-mannose metabolic process Source: Ensembl
GPI anchor biosynthetic process Source: UniProtKB
Protein mannosylation Source: HGNC-UCL
Protein O-linked mannosylation Source: HGNC-UCL

Cellular Location

Endoplasmic reticulum

Involvement in disease

Congenital disorder of glycosylation 1E (CDG1E):
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 CDG1E patients have features consistent with a dystroglycanopathy and congenital muscular dystrophy, including O-mannosylation defect, camptodactyly, elevated creatine kinase, motor delay and dystrophic changes on muscel biopsy.