Carbohydrate Sulfotransferase 1 (CHST1)

The keratan sulfate proteoglycans lumican and keratocan are the major proteoglycans in the cornea and are thought to play an important role in corneal transparency. Sulfation appears to be important for the biologic function of keratan sulfate, because undersulfated keratan sulfate is synthesized in patients with macular corneal dystrophy. A slightly larger and less abundant transcript was observed in human skeletal muscle. The predicted 411-amino acid KSGal6ST shares 37% sequence identity with chick C6ST. When the KSGal6ST cDNA was expressed in COS-7 cells, keratan sulfate sulfotransferase activity increased, but C6ST activity did not. In vitro, the partially purified KSGal6ST protein showed substrate specificity towards keratan sulfate; KSGal6ST could not utilize chondroitin as an acceptor.