Table 1: Designation of the six human enzymes associated with chondroitin sulfate glycosaminoglycan chain polymerization. Note that an additional eight or more enzymes can be involved in the synthesis of GAG chains, some of which may impact of GAG elongation, but this table and paper focuses on those enzymes primarily involved in GAG chain polymerization

Transferase/Polymerase Name1 EC Number2 Gene Name References
Chondroitin sulfate
N-acetylgalactosaminyltransferase 1
CGAT1 2.4.1.174 CSGALNACT1 [26, 27]
Chondroitin sulfate
N-acetylgalactosaminyltransferase 2
CGAT2 2.4.1.174 CSGALNACT2 [53, 28]
Chondroitin sulfate glucuronyltransferase CHGUT 2.4.1.226 CSGLCAT [26]
Chondroitin sulfate synthase 1 CHSS1 2.4.1.226
2.4.1.175
CHSY1 [24, 29]
Chondroitin sulfate synthase 2 CHSS2 2.4.1.226
2.4.1.175
CHPF [29]
Chondroitin sulfate synthase 3 CHSS3 2.4.1.226
2.4.1.175
CHSY3 [31]

1 Nomenclature of the UniProt Knowledgebase of ExPASy Proteomics server.
2 Transferase activities are: EC 2.4.1.174, EC 2.4.1.175 is N-acetylgalactosaminyltransferase (GalNAc transferase) activity; EC 2.4.1.226 is Glucuronyltransferase (GlcA transferase) activity.