Enables N-acetylgalactosamine 4-O-sulfotransferase activity. Acts upstream of or within proteoglycan biosynthetic process. Predicted to be located in Golgi apparatus and membrane. Predicted to be integral component of membrane. Is expressed in several structures, including foregut; genitourinary system; heart; nervous system; and pelvic girdle skeleton. Human ortholog(s) of this gene implicated in peeling skin syndrome. Orthologous to human CHST8 (carbohydrate sulfotransferase 8). [provided by Alliance of Genome Resources, Apr 2022]