Chondroitin beta-1,4-N-acetylgalactosaminyltransferase 1; beta4GalNAcT-1 (GALNACT1, CHGN, CSGALNACT1, UNQ656/PRO1287)

Function

• transfers 1,4-N-acetylgalactosamine (GalNAc) from UDP-GalNAc to the nonreducing end of glucuronic acid (GlcUA)
• required for addition of the first GalNAc to the core tetrasaccharide linker & for elongation of chondroitin chains

UDP-N-acetyl-D-galactosamine + beta-D-glucuronyl-1,3-D-galactosyl-proteoglycan <--> UDP + N-acetyl-D-galactosaminyl-1,4-beta-D-glucuronyl-1,3-beta- D-galactosylproteoglycan

Structure

• N-glycosylated
• belongs to the chondroitin N-acetylgalactosaminyltransferase family

Compartment

Golgi, Golgi membrane

Alternative splicing

named isoforms=3

Expression

• ubiquitous
• highest levels in placenta, thyroid, bladder, prostate & adrenal gland
• detected at low levels in the other tissues examined

More general terms

• chondroitin beta-1,4-N-acetylgalactosaminyltransferase (GALNACT)

Database

• UniProt: http://www.uniprot.org/uniprot/Q8TDX6.html