Sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) as sulfonate donor to catalyze the transfer of sulfate to position 6 of non-reducing N-acetylglucosamine (GlcNAc) residues within keratan-like structures on N-linked glycans and within mucin-associated glycans that can ultimately serve as SELL ligands. SELL ligands are present in high endothelial cells (HEVs) and play a central role in lymphocyte homing at sites of inflammation. Participates in biosynthesis of the SELL ligand sialyl 6-sulfo Lewis X and in lymphocyte homing to Peyer patches. Has no activity toward O-linked sugars. Its substrate specificity may be influenced by its subcellular location. Sulfates GlcNAc residues at terminal, non-reducing ends of oligosaccharide chains. 3'-phosphoadenylyl sulfate + 3-O-{N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D-galactosyl-(1->3)-N-acetyl-alpha-D-galactosaminyl}-L-threonyl-[protein] = 3-O-{6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D-galactosyl-(1->3)-N-acetyl-alpha-D-galactosaminyl}-L-threonyl-[protein] + adenosine 3',5'-bisphosphate + H(+) 3'-phosphoadenylyl sulfate + 3-O-{N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D-galactosyl-(1->3)-N-acetyl-alpha-D-galactosaminyl}-L-seryl-[protein] = 3-O-{6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D-galactosyl-(1->3)-N-acetyl-alpha-D-galactosaminyl}-L-seryl-[protein] + adenosine 3',5'-bisphosphate + H(+) 3'-phosphoadenylyl sulfate + 3-O-{beta-D-galactosyl-(1->3)-[N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-threonyl-[protein] = 3-O-{beta-D-galactosyl-(1->3)-[6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-threonyl-[protein] + adenosine 3',5'-bisphosphate + H(+) 3'-phosphoadenylyl sulfate + 3-O-{beta-D-galactosyl-(1->3)-[N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-seryl-[protein] = 3-O-{beta-D-galactosyl-(1->3)-[6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-seryl-[protein] + adenosine 3',5'-bisphosphate + H(+) Protein modification; carbohydrate sulfation. Homodimer; disulfide-linked. Homodimerization is not essential for enzyme activity (By similarity). In brain, it is expressed in pyramidal cells in the CA3 subregion of the hippocampus, cerebellar nucleus and Purkinje cells. Expressed in peripheral lymph nodes. Mice are impaired in the elaboration of sialyl 6-sulfo Lewis X in HEV. Lymphocyte homing to peripheral lymph nodes, mesenteric lymph nodes, and Peyer patches are significantly reduced. Simultaneous knockdown of CHST4 and CHST2 results in lower contact hypersensitivity response when compared to wild-type littermates. Belongs to the sulfotransferase 1 family. Gal/GlcNAc/GalNAc subfamily. It is uncertain whether Met-1 or Met-48 is the initiator.