Sulfotransferase involved in SELL/L-selectin ligand biosynthesis pathway. Catalyzes the transfer of the sulfate group from 3'-phospho-5'-adenylyl sulfate (PAPS) onto the hydroxyl group at C-6 position of the non-reducing N-acetylglucosamine (GlcNAc) residue within O-linked mucin-type glycans (PubMed:10435581, PubMed:16227985, PubMed:15319280, PubMed:16227986, PubMed:14597732, PubMed:15111310). Contributes to generate sialyl 6-sulfo Lewis X determinant (also known as MECA-79 epitope) for SELL recognition, a prerequisite for continuous lymphocyte homing into peripheral lymph nodes and antigen immune surveillance. Transfers the sulfate group primarily on core 2 GlcNAcbeta1-6(Galbeta1-3)GalNAcalphaSer/Thr and extended core 1 GlcNAcbeta1-3Galbeta1-3GalNAcalphaSer/Thr based O-linked glycans on CD34 and GLYCAM1 peripheral node addressins (PNAds) expressed on the lumenal side of high endothelial venules (HEVs) (PubMed:10435581, PubMed:16227985, PubMed:15319280, PubMed:16227986, PubMed:15111310, PubMed:14593101). The recognition of PNAds by SELL initiates a multistep process comprising tethering and rolling of blood lymphocytes on HEVs against the blood flow, followed by chemokine signaling, integrin-mediated lymphocyte adhesion onto endothelial cells and lymphocyte transendothelial migration. Modulates rolling velocity and differential T and B lymphocyte recruitment into peripheral lymph nodes, with a major role in B lymphocyte homing (PubMed:16227985, PubMed:15319280, PubMed:16227986, PubMed:14597732, PubMed:10435581). Might be redundant in sulfation of MADCAM1 and lymphocyte trafficking to mesenteric lymph nodes (PubMed:10435581, PubMed:11520459, PubMed:16227986). Can also sulfonate core 3 GlcNAcbeta1-3GalNAc-R based glycans as well as GlcNAcbeta1-3Galbeta1-Glc, GlcNAcbeta1-6ManOMe and GlcNAcbeta1-2Man oligosaccharides, which might be ectopically expressed during tumorigenesis (By similarity). 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. Monomer. Specifically expressed in high endothelial venules (HEV) of peripheral lymph nodes. Mice are impaired in lymphocyte homing and exhibit faster lymphocyte rolling and reduced lymphocyte sticking in HEV. The epitope of SELL ligands recognized by the MECA-79 antibody is greatly reduced or abolished in the abluminal aspect of HEV. 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.