Carbohydrate sulfotransferase 15 (CHST15)

Sulfotransferase that transfers sulfate from 3'- phosphoadenosine 5'-phosphosulfate (PAPS) to the C-6 hydroxyl group of the GalNAc 4-sulfate residue of chondroitin sulfate A and forms chondroitin sulfate E containing GlcA-GalNAc(4,6-SO(4)) repeating units. Additionally, it transfers sulfate to a unique non- reducing terminal series, GalNAc(4SO4)-GlcA(2SO4)-GalNAc(6SO4), to yield an extremely sulfated structure similar to the structure found in thrombomodulin chondroitin sulfate.

May also act as a B- cell receptor involved in BCR ligation-mediated early activation that mediate regulatory signs key to B-cell regulation or development of B-cell-specific RAG expression; however such results are unclear in vivo. .