ZFIN ID: ZDB-PUB-060323-9
Perturbation of rRNA synthesis in the bap28 mutation leads to apoptosis mediated by p53 in the zebrafish central nervous system
Azuma, M., Toyama, R., Laver, E., and Dawid, I.B.
Date: 2006
Source: The Journal of biological chemistry   281(19): 13309-13316 (Journal)
Registered Authors: Azuma, Mizuki, Dawid, Igor B., Laver, Elizabeth, Toyama, Reiko
Keywords: none
MeSH Terms:
  • Animals
  • Apoptosis/physiology*
  • Brain/growth & development
  • Brain/metabolism
  • Central Nervous System/metabolism*
  • Gene Expression Regulation, Developmental
  • Mutation
  • RNA, Ribosomal/biosynthesis*
  • RNA, Ribosomal, 18S/metabolism
  • Ribosomes/metabolism
  • Tumor Suppressor Protein p53/metabolism*
  • Zebrafish
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed: 16531401 Full text @ J. Biol. Chem.
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ABSTRACT
Zebrafish is a powerful vertebrate model system for using forward genetics to elucidate mechanisms of early development. We have used chemical mutagenesis to screen for mutants that show defects in the CNS. Here we describe the isolation of the bap28 mutation that leads to abnormalities in the brain starting at mid somitogenesis stages. Mutant embryos display excess apoptosis primarily in the CNS, and die by day 6-7 after fertilization. The mutation was positionally cloned and shown to affect a gene that encodes a large protein with high similarity to the uncharacterized human protein BAP28, and lower similarity to yeast Utp10. Utp10 is a component of a nucleolar U3 snoRNA-containing RNP complex that is required for transcription of rDNA and for processing of 18S rRNA. We show that zebrafish Bap28 likewise is required for rRNA transcription and processing, with a major effect on 18S rRNA maturation. We suggest that bap28 is required for cell survival in the CNS through its role in rRNA synthesis and processing. Inhibition of p53 protein expression in bap28 mutants led to embryos with morphologically normal appearance, suggesting that p53 is involved in triggering apoptosis in the bap28 mutant CNS. The bap28 mutation provides a genetic approach to study the role of ribosome biogenesis in the development of a vertebrate embryo.
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