Diamond-Blackfan anemia (DBA) is associated with developmental defects and profound anemia. Mutations in genes encoding a ribosomal protein of the small (e.g., RPS19) or large (e.g., RPL11) ribosomal subunit are found in more than half of these patients. The mutations cause ribosomal haploinsufficiency, which reduces overall translation efficiency of cellular mRNAs. We reduced the expression of Rps19 or Rpl11 in mouse erythroblasts and investigated mRNA polyribosome association, which revealed deregulated translation initiation of specific transcripts. Among these were Bag1, encoding a Hsp70 cochaperone, and Csde1, encoding an RNA-binding protein, and both were expressed at increased levels in erythroblasts. Their translation initiation is cap independent and starts from an internal ribosomal entry site, which appeared sensitive to knockdown of Rps19 or Rpl11. Mouse embryos lacking Bag1 die at embryonic day 13.5, with reduced erythroid colony forming cells in the fetal liver, and low Bag1 expression impairs erythroid differentiation in vitro. Reduced expression of Csde1 impairs the proliferation and differentiation of erythroid blasts. Protein but not mRNA expression of BAG1 and CSDE1 was reduced in erythroblasts cultured from DBA patients. Our data suggest that impaired internal ribosomal entry site-mediated translation of mRNAs expressed at increased levels in erythroblasts contributes to the erythroid phenotype of DBA.
- MeSH
- biologické markery * metabolismus MeSH
- buněčná diferenciace * MeSH
- Diamondova-Blackfanova anemie * genetika patologie MeSH
- DNA vazebné proteiny genetika metabolismus fyziologie MeSH
- embryo savčí cytologie metabolismus MeSH
- erytroblasty * cytologie metabolismus MeSH
- fenotyp MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- lidé MeSH
- malá interferující RNA genetika MeSH
- messenger RNA genetika metabolismus MeSH
- mutace genetika MeSH
- myši knockoutované MeSH
- myši MeSH
- polyribozomy * genetika metabolismus patologie MeSH
- proliferace buněk MeSH
- proteiny vázající RNA genetika metabolismus MeSH
- proteosyntéza * MeSH
- průtoková cytometrie MeSH
- ribozomální proteiny antagonisté a inhibitory genetika metabolismus MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- stanovení celkové genové exprese MeSH
- transkripční faktory genetika metabolismus fyziologie MeSH
- western blotting MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
