Contributes to serine C-palmitoyltransferase activity. Acts upstream of or within ceramide biosynthetic process; endoplasmic reticulum organization; and regulation of serine C-palmitoyltransferase activity. Part of serine C-palmitoyltransferase complex. Is expressed in central nervous system; eye; genitourinary system; and gut. Orthologous to human SPTSSB (serine palmitoyltransferase small subunit B). [provided by Alliance of Genome Resources, Apr 2022]