Ethanolamine phosphate transferase involved in glycosylphosphatidylinositol-anchor biosynthesis. Transfers ethanolamine phosphate to the first alpha-1,4-linked mannose of the glycosylphosphatidylinositol precursor of GPI-anchor (By similarity). May act as suppressor of replication stress and chromosome missegregation.
Subcellular locations: Endoplasmic reticulum membrane