sialyltransferase 6; N-acetyllactosaminide alpha-2,3-sialyltransferase; CMP-N-acetylneuraminate-beta-1,4-galactoside alpha-2,3-sialyltransferase; Gal beta-1,3(4) GlcNAc alpha-2,3 sialyltransferase (ST3N, ST3GalII, SIAT6, ST3GAL3)

Function

• catalyzes the formation of the neuAc-alpha-2,3-gal-beta-1,4-GlcNAc-, neuAc-alpha-2,3-gal-beta-1,3-GlcNAc- or neuAc-alpha-2,3-gal-beta-1,3-galNAc- sequences found in terminal carbohydrate groups of glycoproteins & glycolipids
• highest activity is toward gal-beta-1,3-GlcNAc & the lowest toward gal-beta-1,3-galNAc (putative)
• protein modification; protein glycosylation
• the soluble form derives from the membrane form by proteolytic processing

CMP-N-acetylneuraminate +
beta-D-galactosyl-1,4-N-acetyl-D-glucosaminyl-glycoprotein
               <-->
CMP + alpha-N-acetylneuraminyl-2,3-beta-D-galactosyl-1,4-N- acetyl-D-glucosaminyl-glycoprotein

Structure

belongs to the glycosyltransferase 29 family

Compartment

• Golgi, Golgi stack membrane
• secreted
• membrane-bound form in trans cisternae of Golgi
• secreted into the body fluid

Alternative splicing

named isoforms=26

Expression

• highly expressed in adult skeletal muscle & in all fetal tissues examined & to a much lesser extent in placenta, lung & liver

More general terms

• sialyltransferase
• galactosyltransferase
• membrane protein
• glycoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/Q11203.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:6487
• OMIM: https://mirror.omim.org/entry/606494
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=6487