Mediates the formation of endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) foci, thereby contributing to the formation of ER-mitochondrial contact sites. Interacts with the ER-mitochondria encounter structure (ERMES) complex (PubMed:33483504). Interacts with mdm12 (PubMed:33483504). Interacts with mdm34 (PubMed:33483504). Decreases the number of ER-mitochondria encounter structure (ERMES) foci in cells (PubMed:33483504). Abnormal mitochondrial organization within cells, manifesting as fragmented or aggregated mitochondria, spherical mitochondria, or absence of mitochondria (PubMed:33483504). Decreases the level of phosphatidylethanolamine (PE) in cells (PubMed:33483504). Decreases growth on glucose (fermentable) and glycerol (non-fermentable) carbon sources (PubMed:33483504). Simultaneous disruption of ept1, psd2 or psd3 leads to decreased growth on glucose carbon source (PubMed:33483504). Belongs to the EMR1 family.