POMT1

OMIM: 607423
UniProt: Q9Y6A1

Protein -O- mannosyltransferase 1 ( POMT1, Eng. Protein O- mannosyl transferase 1 ) is an enzyme in eukaryotes that belongs to the group of glycosyltransferases. It is encoded by the POMT1 gene, which is localized in humans on the long arm of chromosome 9 ( 9q34.13 ). Mutations in this gene can lead to rare genetic diseases. POMT1 is involved in the so-called O-glycosylation of proteins.

The enzyme is anchored as a " multi-pass " transmembrane proteins in the lipid bilayer of the endoplasmic reticulum and is formed in many cells ( expressed). A high concentration was found in the testis, heart muscle and pancreas. Lower concentrations used in the kidneys, skeletal muscle, brain, placenta, lung and liver.

Function

POMT1 can only be enzymatically active when it as a protein complex with another glycosyltransferase, protein -O- mannosyltransferase 2 ( POMT2 ) is present. POMT1 and POMT2 together catalyze the bonding of the sugar mannose via an O - glycosidic linkage 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- Mannosylglykane be 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 to the extracellular matrix. Mutations in the gene or POMT1 POMT2 gene, the O- glycosylation of the α - Dystroglykans is disturbed, so that there may be conditions. Several belonging to the group of diseases or phenotypes Dystroglykanopathien known which are associated with mutations in the gene POMT1:

The congenital muscular dystrophies POMT1 -associated Walker - Warburg syndrome and muscle - associated POMT1 eye-brain disease,
Congenital muscular dystrophy with mental retardation Dystroglykanopathie type B1 ( MDDGB1 ) and
The limb- LGMD2K.

POMT1

Function

Medical importance

Further Reading