Protein O-mannosyltransferase 2
| Protein O-mannosyltransferase 2 | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 750 AA | |
| Cofactor | Mg ++ | |
| Isoforms | 2 | |
| Identifier | ||
| Gene name | POMT2 | |
| External IDs | ||
| Enzyme classification | ||
| EC, category | 2.4.1.109 , glycosyl transferase | |
| Response type | Transfer of a mannosyl residue | |
| Substrate | Dolichyl phosphate D-mannose + protein | |
| Products | Dolichyl phosphate + O-mannosyl protein | |
| Occurrence | ||
| Parent taxon | Eukaryotes , bacteria | |
Protein-O-mannosyltransferase 2 (POMT2) is an enzyme in eukaryotes that belongs to the group of glycosyltransferases . It is through the POMT2 gene encoding that in humans on the long arm of chromosome 14 is located (14q24.3). Mutations in this gene can lead to rare hereditary diseases. POMT2 is involved in the so-called O-glycosylation of proteins .
The enzyme is anchored as a “multipass” transmembrane protein in the lipid bilayer of the endoplasmic reticulum and is formed ( expressed ) in numerous cells .
function
POMT2 can only become enzymatically active if it is present as a protein complex with another glycosyltransferase, protein-O-mannosyltransferase 1 (POMT1). POMT1 and POMT2 together catalyze the binding of the sugar mannose via an O-glycosidic bond to the serine / threonine side chains of the protein. This is an important step in the post-translational modification of proteins.
Medical importance
In mammals, O-mannosylglycans are found mainly in the α-dystroglycan . α-Dystroglycan is an important component of the dystrophin-glycoprotein complex in muscle and nerve cells, which is used to connect the cytoskeleton with the extracellular matrix. Mutations in the POMT1 gene or POMT2 gene disrupt the O-glycosylation of the α-dystroglycan, so that diseases can occur. Several diseases or phenotypes belonging to the group of dystroglycanopathies are known that are associated with mutations in the POMT2 gene :
- the congenital muscular dystrophies POMT1-associated Walker-Warburg syndrome and POMT2-associated muscle-eye-brain disease ,
- the Congenital Muscular Dystrophy Dystroglykanopathie with mental retardation type B2 (MDDGB2) and
- the limb-2N (LGMD2N).
literature
- K. Akasaka-Manya, H. Manya et al. a .: Different roles of the two components of human protein O-mannosyltransferase, POMT1 and POMT2. In: Biochemical and biophysical research communications Volume 411, Number 4, August 2011, pp. 721-725, doi : 10.1016 / j.bbrc . 2011.07.012 , PMID 21782786 .
Individual evidence
- ↑ UniProt search EC: 2.4.1.109 by taxonomy
- ↑ POMT2. In: Online Mendelian Inheritance in Man . (English)
- ↑ UniProt Q9UKY4
- ↑ a b B. Prados, A. Peña et al .: Expression of the murine Pomt1 gene in both the developing brain and adult muscle tissues and its relationship with clinical aspects of Walker-Warburg syndrome. In: The American Journal of Pathology , Volume 170, Number 5, May 2007, pp. 1659-1668, doi : 10.2353 / ajpath.2007.061264 , PMID 17456771 , PMC 185496 (free full text).
- ↑ MDDGA2. In: Online Mendelian Inheritance in Man . (English)
- ↑ C. Godfrey, E. Clement et al .: Refining genotype phenotype correlations in muscular dystrophies with defective glycosylation of dystroglycan. In: Brain: a journal of neurology Volume 130, Pt 10, October 2007, pp. 2725-2735, doi : 10.1093 / brain / awm212 . PMID 17878207 .
- ↑ E. Mercuri, S. Messina et al. a .: Congenital muscular dystrophies with defective glycosylation of dystroglycan: a population study. In: Neurology Volume 72, Number 21, May 2009, pp. 1802-1809, doi : 10.1212 / 01.wnl.0000346518.68110.60 , PMID 19299310 .
- ↑ MDDGB2. In: Online Mendelian Inheritance in Man . (English)
- ↑ LGMD2N. In: Online Mendelian Inheritance in Man . (English)