Characterization of NF-kappa B/I kappa B proteins in zebra fish and their involvement in notochord development

Correa, R.G., Tergaonkar, V., Ng, J.K., Dubova, I., Izpisúa Belmonte, J.C., and Verma, I.M.
Molecular and cellular biology   24(12): 5257-5268 (Journal)
Registered Authors
Dubova, Ilir, M.D., Izpisúa Belmonte, Juan Carlos, Ng, Jennifer
MeSH Terms
  • Animals
  • Cells, Cultured
  • DNA, Complementary/genetics
  • Fetal Proteins
  • Gene Expression Regulation, Developmental
  • Humans
  • I-kappa B Proteins/genetics
  • I-kappa B Proteins/metabolism*
  • Mice
  • Mice, Knockout
  • NF-kappa B/genetics
  • NF-kappa B/metabolism*
  • Notochord/embryology*
  • Notochord/metabolism
  • Phenotype
  • Recombinant Proteins/genetics
  • Recombinant Proteins/metabolism
  • Species Specificity
  • T-Box Domain Proteins/genetics
  • T-Box Domain Proteins/metabolism
  • Zebrafish/embryology*
  • Zebrafish/genetics
  • Zebrafish/metabolism*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
15169890 Full text @ Mol. Cell. Biol.
Although largely involved in innate and adaptive immunity, NF-kappa B plays an important role in vertebrate development. In chicks, the inactivation of the NF-kappa B pathway induces functional alterations of the apical ectodermal ridge, which mediates limb outgrowth. In mice, the complete absence of NF-kappa B activity leads to prenatal death and neural tube defects. Here, we report the cloning and characterization of NF-kappa B/I kappa B proteins in zebra fish. Despite being ubiquitously expressed among the embryonic tissues, NF-kappa B/I kappa B members present distinct patterns of gene expression during the early zebra fish development. Biochemical assays indicate that zebra fish NF-kappa B proteins are able to bind consensus DNA-binding (kappa B) sites and inhibitory I kappa B alpha proteins from mammals. We show that zebra fish I kappa B alphas are degraded in a time-dependent manner after induction of transduced murine embryo fibroblasts (MEFs) and that these proteins are able to rescue NF-kappa B activity in I kappa B alpha(-/-) MEFs. Expression of a dominant-negative form of the murine I kappa B alpha (mI kappa B alpha M), which is able to block NF-kappa B in zebra fish cells, interferes with the notochord differentiation, generating no tail (ntl)-like embryos. This phenotype can be rescued by coinjection of the T-box gene ntl (Brachyury homologue), which is typically required for the formation of posterior mesoderm and axial development, suggesting that ntl lies downstream of NF-kappa B . We further show that ntl and Brachyury promoter regions contain functional kappa B sites and NF-kappa B can directly modulate ntl expression. Our study illustrates the conservation and compatibility of NF-kappa B/I kappa B proteins among vertebrates and the importance of NF-kappa B pathway in mesoderm formation during early embryogenesis.
Genes / Markers
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Engineered Foreign Genes
Errata and Notes