KEGG Pathway Report
Basic Info
ID |
hsa00532
|
Name |
Glycosaminoglycan biosynthesis - chondroitin sulfate |
Description |
Glycosaminoglycans (GAGs) are linear polysaccharide chains consisting of repeating disaccharide units and form proteglycans by covalently attaching to their core proteins. Chondroitin sulfate (CS) is a glycosaminoglycan with the disaccharide unit GalNAc(b1-4)GlcA(b1-3), modified with ester-linked sulfate at certain positions. Dermatan sulfate (DS) is a modified form of CS, in which a portion of D-glucuronate residues is epimerized to L-iduronates. CS and DS are linked to serine residues in core proteins via a linkage tetrasaccharide formed by the transfer of xylose and three more residues [MD:M00057]. The assembly process of CS is initiated by the transfer of N-acetylgalactosamine to the linkage tetrasaccharide. The polymerization step is catalyzed by bifunctional enzymes (chondroitin synthases) that have both b1-3 glucuronosyltransferase and b1-4 N-acetylgalactosaminyltransferase activities [MD:M00058]. Chondroitin polymerization also requires the action of the chondroitin polymerizing factor. Sulfation of chondroitin in vertebrates is a complex process, with multiple sulfotransferases involved in 4-O sulfation and 6-O sulfation of N-acetylgalactosamine residues. Additional enzymes exist for epimerization of glucuronic acid to iduronic acid in DS, sulfation at the C-2 position of the uronic acids, and other patterns of sulfation found in unusual species of chondroitin. |
No. of Genes in ADHDgene |
5 |
Source |
Pathway by Database Search
|
Pathway related genes in ADHDgene (count: 5)