bifunctional UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase; UDP-GlcNAc-2-epimerase/manAc kinase; includes: UDP-N-acetylglucosamine 2-epimerase; UDP-GlcNAc-2-epimerase; uridine diphosphate-N-acetylglucosamine-2-epimerase; N-acetylmannosamine kinase; manAc kinase (GNE, GLCNE)

Function

• biosynthesis of N-acetylneuraminic acid
• role in early development
• sialylation in hematopoietic cells
• allosterically regulated: (feedback inhibition)
• inhibited by cytidine monophosphate-N-acetylneuraminic acid, end product of neuraminic acid biosynthesis
• phosphorylated by PKC

Structure

• oligomerization
• monomer is inactive
• dimer catalyzes only phosphorylation of N-acetylmannosamine
• hexamer fully active for both enzyme activities

Expression

• expressed in liver, placenta > heart, brain, lung, kidney, skeletal muscle, pancreas
• up-regulated after PKC-dependent phosphorylation.

Pathology

• defects in GNE are the cause of:
  • sialuria
  • inclusion body myopathy 2
  • Nonaka distal myopathy

More general terms

• kinase or ATP-phosphotransferase
• epimerase
• oligomerizing protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=10020
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:10020
• OMIM: https://mirror.omim.org/entry/269921
• OMIM: https://mirror.omim.org/entry/600737
• OMIM: https://mirror.omim.org/entry/603824
• OMIM: https://mirror.omim.org/entry/605820
• UniProt: http://www.uniprot.org/uniprot/Q9Y223.html