dpm1 (S. pombe, SPAC31G5.16c, UniProt O14466) notes

Identity

• UniProt O14466 (DPM1_SCHPO), 236 aa, PomBase SPAC31G5.16c; fetched accession verified against the request.
• Glycosyltransferase family 2; PANTHER PTHR43398:SF1 [UniProt:O14466].

Function

• Catalytic subunit of dolichol-phosphate-mannose (Dol-P-Man) synthase, EC 2.4.1.83 (by similarity to human O60762) [UniProt:O14466 "Transfers mannose from GDP-mannose to dolichol monophosphate"].
• Cloned by Colussi et al.; the gene is essential: PMID:9223280
• Belongs to the human-type class lacking a C-terminal TM anchor: PMID:9223280.
• Functional equivalence with S. cerevisiae DPM1 and human DPM1, which both rescue the null PMID:9223280; membranes of rescued haploids had Dol-P-Man synthase activity PMID:9223280. No GOA row uses this paper; the MF is supported only by ISS/IBA/IEA in GOA, but the paper supports it for the S. pombe protein (complementation by heterologous enzymes plus the 65% identity to human DPM1).
• S. pombe has all three subunits PMID:10835346.

Location

• ER (and cytoplasm) in the ORFeome YFP screen PMID:16823372. As a TM-less catalytic subunit it sits on the cytoplasmic face of the ER membrane, tethered by dpm3 (human data, PMID:16280320).

Comparison with S. cerevisiae DPM1 (genes/yeast/DPM1)

• Same MF (GO:0004582) and BP (GO:0180047). Difference: S. cerevisiae Dpm1 is a single-subunit anchored enzyme; S. pombe dpm1 is the catalytic subunit of the three-subunit complex (GO:0033185).

GO-CAM

• PomBase gomodel:671ae02600003596 activity 671ae02600003597: dpm1 enables GO:0004582, occurs_in ER membrane, part_of GO:0180047 (IBA). Agrees.

Annotation notes

• GO:0046474 glycerophospholipid biosynthetic process (ARBA): Dol-P-Man is a polyprenyl-phosphate sugar, not a glycerophospholipid; the term can only be reached through the downstream GPI-anchor use. Over-annotation.
• GO:0051604 protein maturation (ARBA): too indirect.