Title |
Addition of α-O-GlcNAc to threonine residues define the post-translational modification of mucin-like molecules in Trypanosoma cruzi
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Published in |
Glycoconjugate Journal, February 2013
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DOI | 10.1007/s10719-013-9469-7 |
Pubmed ID | |
Authors |
Lucia Mendonça-Previato, Luciana Penha, Tatiana Cortes Garcez, Christopher Jones, Jose Osvaldo Previato |
Abstract |
Trypanosoma cruzi, an intracellular protozoan etiologic agent of Chagas disease is covered by a dense coat of mucin-type glycoproteins, which is important to promote the parasite entry and persistence in the mammalian host cells. The O-glycosylation of T. cruzi mucins (Tc-mucins) is initiated by enzymatic addition of α-O-N-acetylglucosamine (GlcNAc) to threonine (Thr) by the UDP-GlcNAc:polypeptide α-N-acetylglucosaminyltransferase (pp-α-GlcNAcT) in the Golgi. The Tc-mucin is characterized by the presence of a high structural diversity of O-linked oligosaccharides found among different parasite strains, comprising two O-glycan Cores. In the Core 1, from strains principally associated with the domestic transmission cycle of Chagas disease, the GlcNAc O-4 is substituted with a β-galactopyranose (βGalp) unit, and in the most complex oligosaccharides the GlcNAc O-6 is further processed by the addition of β1 → 2-linked Galp residues creating a short linear Galp-containing chain. In the Core 2 structures, expressed by strains isolated from T. cruzi sylvatic hosts, the GlcNAc O-4 carries a β-galactofuranose (βGalf) unit and the GlcNAc O-6 can carry a branched Galpβ1 → 3[Galpβ1 → 2]Galpβ1 → 6 motif. The O-glycans carrying nonreducing terminal βGalp are available for sialylation by a surface T. cruzi trans-sialidase activity. Based on structural results, this review summarizes available data on the highly conserved process, which adds the GlcNAc unit in α-linkage to Thr residues the basis of the post-translational modification system in T. cruzi mucins. In addition, a mechanism unique employed by the parasite to transfer exogenous sialic acid residues to Tc-mucins is presented. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
China | 1 | 2% |
France | 1 | 2% |
Unknown | 51 | 96% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Ph. D. Student | 10 | 19% |
Professor > Associate Professor | 7 | 13% |
Student > Doctoral Student | 6 | 11% |
Researcher | 6 | 11% |
Student > Master | 6 | 11% |
Other | 8 | 15% |
Unknown | 10 | 19% |
Readers by discipline | Count | As % |
---|---|---|
Biochemistry, Genetics and Molecular Biology | 16 | 30% |
Agricultural and Biological Sciences | 11 | 21% |
Immunology and Microbiology | 5 | 9% |
Chemistry | 4 | 8% |
Medicine and Dentistry | 3 | 6% |
Other | 2 | 4% |
Unknown | 12 | 23% |