protein O-mannosyl-transferase 1; dolichyl-phosphate-mannose-protein mannosyltransferase 1 (POMT1)

Function

• transfers mannosyl residues to the hydroxyl group of Ser or Thr
• coexpression of both POMT1 & POMT2 is necessary for enzyme activity, expression of either POMT1 or POMT2 alone is insufficient
• protein modification; protein glycosylation
• interacts with POMT2 (probable)

dolichyl phosphate D-mannose + protein = dolichyl phosphate + O-D-mannosylprotein

Cofactor:

• Mg+2
• Mn+2 & Ca+2 suppress enzyme activity

Structure

• belongs to the glycosyltransferase 39 family
• contains 3 MIR domains

Compartment

• endoplasmic reticulum membrane
• multi-pass membrane protein

Alternative splicing

• named isoforms=4
• additional isoforms seem to exist

Expression

• widely expressed
• highly expressed in testis, heart & pancreas
• detected at lower levels in kidney, skeletal muscle, brain, placenta, lung & liver

Pathology

• mutations in POMT1 gene associated with variations in the Walker-Warburg syndrome

More general terms

• transmembrane 12 protein
• glycosyltransferase
• glycoprotein

Additional terms

• dolichol phosphate
• Walker-Warburg syndrome; hydrocephalus, agyria & retinal dysplasia; Hard syndrome; Chemke syndrome; Pagon syndrome; cerebroocular dysplasia-muscular dystrophy syndrome

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=10585
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:10585
• OMIM: https://mirror.omim.org/entry/236670
• OMIM: https://mirror.omim.org/entry/607423
• OMIM: https://mirror.omim.org/entry/609308
• OMIM: https://mirror.omim.org/entry/613155
• UniProt: http://www.uniprot.org/uniprot/Q9Y6A1.html