O-linked glycosylation of mucins

Reviewed: Ferrer, A, 2011-11-04 Authored: Jassal, B, 2010-07-19 Edited: Jassal, B, 2010-07-19 Mucins are a family of high molecular weight, heavily glycosylated proteins (glycoconjugates) produced by epithelial tissues in most metazoa. Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell signalling to forming chemical barriers. To date, there are approximately 20 genes that express mucins. Mature mucins are composed of two distinct regions:<br>(1) The amino- and carboxy-terminal regions are very lightly glycosylated, but rich in cysteines. The cysteine residues participate in establishing disulfide linkages within and among mucin monomers.<br>(2) A large central region rich in serine, threonine and proline residues called the variable number of tandem repeat (VNTR) region which can become heavily O-glycosylated with hundreds of O-GalNAc glycans.<br> N-acetyl-galactosamine (GalNAc) is the first glycan to be attached, forming the simplest mucin O-glycan. After this, several different pathways are possible generating "core" structures. Four core structures are commonly formed, several others are possible but infrequent. O-linked glycans are often capped by the addition of a sialic acid residue, terminating the addition of any more O-glycans (Brockhausen et al, 2009; Tarp and Clausen, 2008).

http://purl.obolibrary.org/obo/HINO_0016810

Reviewed: Ferrer, A, 2011-11-04

Authored: Jassal, B, 2010-07-19

Edited: Jassal, B, 2010-07-19

Mucins are a family of high molecular weight, heavily glycosylated proteins (glycoconjugates) produced by epithelial tissues in most metazoa. Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell signalling to forming chemical barriers. To date, there are approximately 20 genes that express mucins. Mature mucins are composed of two distinct regions:
(1) The amino- and carboxy-terminal regions are very lightly glycosylated, but rich in cysteines. The cysteine residues participate in establishing disulfide linkages within and among mucin monomers.
(2) A large central region rich in serine, threonine and proline residues called the variable number of tandem repeat (VNTR) region which can become heavily O-glycosylated with hundreds of O-GalNAc glycans.
N-acetyl-galactosamine (GalNAc) is the first glycan to be attached, forming the simplest mucin O-glycan. After this, several different pathways are possible generating "core" structures. Four core structures are commonly formed, several others are possible but infrequent. O-linked glycans are often capped by the addition of a sialic acid residue, terminating the addition of any more O-glycans (Brockhausen et al, 2009; Tarp and Clausen, 2008).

Pubmed20301232

Reactome, http://www.reactome.org

Pubmed17988798

O-linked glycosylation of mucins

http://purl.obolibrary.org/obo/NCBITaxon_9606

HINO:0016810

O-linked glycosylation of mucins

Reactome Database ID Release 43913709

ReactomeREACT_115606

GENE ONTOLOGYGO:0016266

http://purl.obolibrary.org/obo/INO_0000021

http://purl.obolibrary.org/obo/HINO_0025649

http://purl.obolibrary.org/obo/HINO_0025648

http://purl.obolibrary.org/obo/HINO_0025647

http://purl.obolibrary.org/obo/HINO_0025655

http://purl.obolibrary.org/obo/HINO_0025654

http://purl.obolibrary.org/obo/HINO_0025651

http://purl.obolibrary.org/obo/HINO_0025653

http://purl.obolibrary.org/obo/HINO_0025652

http://purl.obolibrary.org/obo/HINO_0025650

http://purl.obolibrary.org/obo/HINO_0025656

http://purl.obolibrary.org/obo/HINO_0016809