Predicted to enable beta-galactosyl-N-acetylglucosaminylgalactosylglucosyl-ceramide beta-1,3-acetylglucosaminyltransferase activity. Predicted to be involved in brain development. Predicted to act upstream of or within sphingolipid biosynthetic process. Predicted to be located in Golgi apparatus and membrane. Predicted to be integral component of membrane. Predicted to be active in Golgi membrane. Is expressed in several structures, including alimentary system; eye; genitourinary system; hemolymphoid system gland; and nervous system. Orthologous to human B3GNT5 (UDP-GlcNAc:betaGal beta-1,3-N-acetylglucosaminyltransferase 5). [provided by Alliance of Genome Resources, Apr 2022]