Heparan sulfate (HS) and chondroitin sulfate (CS) are different glycosaminoglycan chains that are attached to core proteins via the same linker tetrasaccharide, and it was unclear how core proteins are specifically modified with HS or CS. Here, the authors determine that the CS-initiating glycosyltransferase CSGALNACT2 is promiscuous, whereas the HS-initiating glycosyltransferase EXTL3 selects only certain core proteins for modification.
- Douglas Sammon
- Anja Krueger
- Erhard Hohenester