Catalyzes the transfer of sulfate to position 4 of non-reducing N-acetylgalactosamine (GalNAc) residues in both N-glycans and O-glycans. Required for biosynthesis of glycoprotein hormones lutropin and thyrotropin, by mediating sulfation of their carbohydrate structures. Only active against terminal GalNAcbeta1,GalNAcbeta. Not active toward chondroitin.
Subcellular locations: Golgi apparatus membrane
Predominantly expressed in pituitary gland. In brain, it is expressed in pituitary gland, cerebellum, medulla oblongata, pons, thalamus and spinal cord. Expressed in the epidermis. Expressed at lower level in lung, spleen, adrenal gland, placenta, prostate, testis, mammary gland and trachea.