PUBLICATION

O-GlcNAc modifications regulate cell survival and epiboly during zebrafish development

Authors
Webster, D.M., Teo, C.F., Sun, Y., Wloga, D., Gay, S., Klonowski, K.D., Wells, L., and Dougan, S.T.
ID
ZDB-PUB-090424-24
Date
2009
Source
BMC Developmental Biology   9: 28 (Journal)
Registered Authors
Dougan, Scott T., Gay, Steven, Sun, Yuhua, Webster, Danielle
Keywords
none
MeSH Terms
  • Acetylglucosamine/metabolism*
  • Animals
  • Apoptosis
  • Blotting, Western
  • Body Patterning
  • Brain/embryology
  • Brain/metabolism
  • Cell Line
  • Cell Survival
  • Cytoskeleton/metabolism
  • Embryonic Stem Cells/cytology
  • Embryonic Stem Cells/metabolism
  • Gene Duplication
  • Gene Expression Regulation, Developmental
  • Germ Layers/metabolism
  • Humans
  • In Situ Hybridization
  • Isoenzymes/genetics
  • Isoenzymes/metabolism
  • Microscopy, Confocal
  • N-Acetylglucosaminyltransferases/classification
  • N-Acetylglucosaminyltransferases/genetics
  • N-Acetylglucosaminyltransferases/metabolism*
  • Octamer Transcription Factor-3/metabolism
  • Phylogeny
  • Protein Processing, Post-Translational
  • Yolk Sac/metabolism
  • Zebrafish/embryology*
  • Zebrafish/genetics
  • Zebrafish/metabolism
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
  • beta-N-Acetylhexosaminidases/genetics
  • beta-N-Acetylhexosaminidases/metabolism
PubMed
19383152 Full text @ BMC Dev. Biol.
Abstract
BACKGROUND: The post-translational addition of the monosaccharide O-linked beta-N-acetylglucosamine (O-GlcNAc) regulates the activity of a wide variety of nuclear and cytoplasmic proteins. The enzymes O-GlcNAc Transferase (OGT) and O-GlcNAcase (OGA) catalyze, respectively, the attachment and removal of O-GlcNAc to target proteins. In adult mice, OGT and OGA attenuate the response to insulin by modifying several components of the signal transduction pathway. Complete loss of ogt function, however, is lethal to mouse embryonic stem cells, suggesting that the enzyme has additional, unstudied roles in development. We have utilized zebrafish as a model to determine role of O-GlcNAc modifications in development. Zebrafish has two ogt genes, encoding six different enzymatic isoforms that are expressed maternally and zygotically. RESULTS: We manipulated O-GlcNAc levels in zebrafish embryos by overexpressing zebrafish ogt, human oga or by injecting morpholinos against ogt transcripts. Each of these treatments results in embryos with shortened body axes and reduced brains at 24hpf. The embryos had 23% fewer cells than controls, and displayed increased rates of cell death as early as the mid-gastrula stages. An extensive marker analysis indicates that derivatives of three germ layers are reduced to variable extents, and the embryos are severely disorganized after gastrulation. Overexpression of OGT and OGA delayed epiboly and caused a severe disorganization of the microtubule and actin based cytoskeleton in the extra-embryonic yolk syncytial layer (YSL). The cytoskeletal defects resemble those previously reported for embryos lacking function of the Pou5f1/Oct4 transcription factor spiel ohne grenzen. Consistent with this, Pou5f1/Oct4 is modified by O-GlcNAc in human embryonic stem cells. CONCLUSIONS: We conclude that O-GlcNAc modifications control the activity of proteins that regulate apoptosis and epiboly movements, but do not seem to regulate germ layer specification. O-GlcNAc modifies the transcription factor Spiel ohne grenzen/Pou5f1 and may regulate its activity.
Genes / Markers
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping