This family consists of several eukaryotic dolichol phosphate-mannose biosynthesis regulatory (DPM2) proteins. Biosynthesis of glycosylphosphatidylinositol and N-glycan precursor is dependent upon a mannosyl donor, dolichol phosphate-mannose (DPM). DPM2, an 84 amino acid membrane protein expressed in the endoplasmic reticulum (ER), makes a complex with DPM1 that is essential for the ER localisation and stable expression of DPM1. Moreover, DPM2 enhances binding of dolichol phosphate, a substrate of DPM synthase. Biosynthesis of DPM in mammalian cells is regulated by DPM2 [1].

1: DPM2 regulates biosynthesis of dolichol phosphate-mannose in mammalian cells: correct subcellular localization and stabilization of DPM1, and binding of dolichol phosphate. Maeda Y, Tomita S, Watanabe R, Ohishi K, Kinoshita T; EMBO J 1998;17:4920-4929. PMID:9724629