Dolichol-phosphate mannose (Dol-P-Man) acts as a donor for mannosylation reactions occurring on the lumenal side of
the endoplasmic reticulum (ER). Dol-P-Man is synthesized from GDP-mannose and dolichol-phosphate on the cytosolic
side of the ER by the enzyme Dol-P-Man synthase (EC 2.4.1.83 ).
NCBI Summary:
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. The protein encoded by this gene is a hydrophobic protein that contains 2 predicted transmembrane domains and a putative ER localization signal near the C terminus. This protein associates with DPM1 in vivo and is required for the ER localization and stable expression of DPM1 and also enhances the binding of dolichol-phosphate to DPM1. Two alternatively spliced transcript variants have been found for this gene.