The function of DPM2 (dolichyl-phosphate mannosyltransferase subunit 2, regulatory, ENSG00000136908) is as follows. 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:16162815). May act by regulating the GPI-GNT complex (PubMed:10944123). {ECO:0000269|PubMed:10835346, ECO:0000269|PubMed:10944123, ECO:0000269|PubMed:16162815}.