Enables sphingosine N-acyltransferase activity. Involved in ceramide biosynthetic process. Acts upstream of or within sphingolipid biosynthetic process. Located in endoplasmic reticulum. Is expressed in several structures, including cardiovascular system; central nervous system; early conceptus; genitourinary system; and gut. Orthologous to human CERS5 (ceramide synthase 5). [provided by Alliance of Genome Resources, Apr 2022]