phosphomannomutase 1; PMM 1; PMMH-22 (PMM1, PMMH22)

Function

• role in the synthesis of the GDP-mannose & dolichol-phosphate-mannose required for a number of critical mannosyl transfer reactions
• in addition, may be responsible for degradation of glucose-1,6-bisphosphate in ischemic brain
• IMP, a metabolite whose concentration is elevated in anoxia, inhibits phosphomannomutase & phosphoglucomutase activities & strongly enhances glucose-1,6-bisphosphatase activity (putative)
• nucleotide-sugar biosynthesis; GDP-alpha-D-mannose biosynthesis; alpha-D-mannose 1-phosphate from D-fructose 6-phosphate: step 2/2

alpha-D-mannose 1-phosphate = D-mannose 6-phosphate

Cofactor: Mg+2

Kinetic parameters:

• KM=54 uM for alpha-D-mannose 1-phosphate
• KM=7.5 uM for alpha-D-glucose 1-phosphate

Structure

• homodimer
• belongs to the eukaryotic PMM family

Compartment

cytoplasm

Expression

• strong expression in liver, heart, brain, & pancreas
• lower expression in skeletal muscle

Laboratory

• phosphomannomutase 1 in fibroblasts
• phosphomannomutase 1 in leukocytes

More general terms

• phosphomannomutase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5372
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5372
• OMIM: https://mirror.omim.org/entry/601786
• UniProt: http://www.uniprot.org/uniprot/Q92871.html