Sialylation is essential for early development in mice

Proc Natl Acad Sci U S A. 2002 Apr 16;99(8):5267-70. doi: 10.1073/pnas.072066199. Epub 2002 Apr 2.


Sialic acids are widely expressed as terminal carbohydrates on glycoconjugates of eukaryotic cells. Sialylation is crucial for a variety of cellular functions, such as cell adhesion or signal recognition, and regulates the biological stability of glycoproteins. The key enzyme of sialic acid biosynthesis is the bifunctional UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (UDP-GlcNAc 2-epimerase), which catalyzes the first two steps of sialic acid biosynthesis in the cytosol. We report that inactivation of the UDP-GlcNAc 2-epimerase by gene targeting causes early embryonic lethality in mice, thereby emphasizing the fundamental role of this bifunctional enzyme and sialylation during development. The need of UDP-GlcNAc 2-epimerase for a defined sialylation process is exemplified with the polysialylation of the neural cell adhesion molecule in embryonic stem cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Animals
  • Blotting, Southern
  • Blotting, Western
  • Carbohydrate Epimerases / chemistry*
  • Carbohydrate Epimerases / genetics*
  • Carbohydrates / chemistry*
  • Catalysis
  • Embryo, Mammalian / cytology
  • Escherichia coli Proteins*
  • Flow Cytometry
  • Gene Targeting
  • Genotype
  • Heterozygote
  • Homozygote
  • Mice
  • Models, Biological
  • Models, Genetic
  • Precipitin Tests
  • Protein Binding
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sialic Acids / chemistry*
  • Stem Cells
  • Time Factors


  • Carbohydrates
  • Escherichia coli Proteins
  • Sialic Acids
  • Carbohydrate Epimerases
  • UDP acetylglucosamine-2-epimerase
  • wecB protein, E coli