beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-N- acetylglucosaminyltransferase 4 (core 2-branching enzyme 3, core2-GlcNAc-transferase 3, C2GnT3, GCNT4)

Function

• glycosyltransferase that mediates core 2 O-glycan branching, a step in mucin-type biosynthesis
• does not have core 4 O-glycan or I-branching enzyme activity
• glycosylation

UDP-N-acetyl-D-glucosamine + beta-D-galactosyl-1,3-N-acetyl-D-galactosaminyl-R <--> UDP + beta-D-galactosyl-1,3-(N-acetyl-beta-D-glucosaminyl-1,6)- N-acetyl-D-galactosaminyl-R

Structure

belongs to the glycosyltransferase 14 family

Compartment

Golgi membrane

Expression

• predominantly expressed in thymus
• weakly expressed in pancreas, peripheral blood leukocytes, placenta, small intestine & stomach
• barely detectable in liver, spleen, lung & lymph node

More general terms

• glycosyltransferase
• membrane protein

Database

• UniProt: http://www.uniprot.org/uniprot/Q9P109.html