CHST1
UniProt:O43916 CHST1
GNS
UniProt:P15586 GNS
HFRC
SLC35D2
UGTREL8
UniProt:Q76EJ3 SLC35D2
SLC35D2 exchanges UDP-sugars for UMP
B4GALTs add galactose to the N-glycan precursor
B3GNT1,2,3,4,7 add GlcNAc to form Keratan-PG
B4GALTs add another galactose to the chain
B4GALTs can add galactose to a branch of keratan
The keratan chain can be capped by N-acetylneuraminic acid
Sulfation of GlcNAc residues on Keratan-PG forms KSPG
Further sulfation on galactose residues produces KSPG
KSPG is secreted from the cell
Extracellular KSPG translocates to the lysosome for degradation
Keratan sulfate is cleaved from its proteoglycan by an unknown galactosidase
N-acetylgalactosamine-6-sulfatase (GALNS) hydrolyses the sulfate groups of galactose 6-sulfate units of keratan sulfate
Beta-galactosidase (GLB1) can cleave galactose from a glycosaminoglycan
N-acetylglucosamine 6-sulfatase (GNS) hydrolyses 6-sulfate groups of the N-acetyl-D-glucosamine 6-sulfate units of keratan sulfate
Beta-hexosaminidase A (BHEXA) cleaves the terminal GalNAc from keratan sulfate
Keratan sulfate/keratin metabolism
Keratan sulfate biosynthesis
Keratan sulfate degradation