DEGS1 is a member of the membrane fatty acid desaturase family which is responsible for inserting double bonds into specific positions in fatty acids. It contains three His containing consensus motifs that are characteristic of a group of membrane fatty acid desaturases. It has sphingolipid-delta-4-desaturase activity and converts D-erythro-sphinganine to D-erythro-sphingosine (E-sphing-4-enine).