beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-N-acetylglucosaminyltransferase 3 (core 2/core 4 beta-1,6-N-acetylglucosaminyltransferase, C2/4GnT, C2GnT-mucin type, C2GnT-M, hC2GnT-M, GCNT3)

Function

• protein glycosylation, mucin biosynthesis
• glycosyltransferase, can synthesize all known mucin beta 6 N-acetylglucosaminides
• mediates core 2 & core 4 O-glycan branching, 2 important steps in mucin-type biosynthesis
• I-branching enzyme activity by converting linear into branched poly-N-acetyllactosaminoglycans, leading to introduce blood group I antigen during embryonic development

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

• N-glycosylated
• belongs to the glycosyltransferase 14 family

Compartment

Golgi membrane

Expression

• primarily expressed in mucus-secreting tissues
• expressed in colon, kidney, small intestine, trachea, & stomach, where mucin is produced
• induced by all-trans retinoic acid, TNF-alpha & IL13

Pathology

• strongly down-regulated in colorectal cancer

More general terms

• glycosyltransferase
• glycoprotein
• membrane protein

Database

• OMIM: https://mirror.omim.org/entry/606836
• UniProt: http://www.uniprot.org/uniprot/O95395.html