mannose-6-phosphate isomerase; phosphomannose isomerase; PMI; phosphohexomutase (MPI, PMI1)

Function

• role in the synthesis of GDP-mannose & dolichol-phosphate-mannose used in mannosyl transfer reactions
• protein modification; protein glycosylation

D-mannose-6-phosphate <--> D-fructose-6-phosphate

Cofactor: binds 1 Zn+2 per subunit (putative)

Structure

• belongs to the mannose-6-phosphate isomerase type 1 family

Compartment

cytoplasm (probable)

Alternative splicing

named isoforms=2

Expression

• expressed in all tissues
• most abundant in heart, brain & skeletal muscle

Pathology

• defects in MPI are the cause of congenital disorder of glycosylation 1B

Laboratory

• MPI gene mutation
• mannose-6-phosphate isomerase measurement
  • mannose-6-phosphate isomerase in leukocytes
  • mannose-6-phosphate isomerase in fibroblasts

More general terms

• mutase

Database

• UniProt: http://www.uniprot.org/uniprot/P34949.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=4351
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4351
• OMIM: https://mirror.omim.org/entry/154550
• OMIM: https://mirror.omim.org/entry/602579