• Corpus ID: 10971826

Translational Control in Heat-shocked Drosophila Embryos

@inproceedings{MarotoS2001TranslationalCI,
  title={Translational Control in Heat-shocked Drosophila Embryos},
  author={Federico G. MarotoS and Jos{\'e} Manuel Sierra},
  year={2001}
}

• Federico G. MarotoS, J. M. Sierra
• Published 2001
• Biology

Lysates from normally growing (25 “C) or heatshocked (37 “C, 45 min) Drosophila melanogaster embryos were obtained and the effect of analogues of the mRNA 5”terminal cap, m7G(5’)ppp(5’)N structure and of potassium ions on their endogenous protein synthesis activity was studied. At optimal concentration of KCHsCOO (75-80 mM), protein synthesis in normal lysates is strongly inhibited by cap analogues (m7GpppG, m7GDP, and m’GMP). At the same ionic conditions, heat shock lysates translate preferentially the heat shock messengers, and this translation is almost unaffected by the cap analogues. In contrast, residual synthesis of normal proteins in heat shock lysates was reduced by these compounds. By lowering the concentration of potassium ions it was possible to gradually reverse the inhibitory effect of the cap analogues in normal lysates and also to increase specifically the translation of normal mRNAs in heat shock lysates. Translation of normal mRNAs is also partial but specifically rescued by supplementing heat shock lysates with polypeptide chain initiation factors partially purified from rabbit reticulocytes. These data are consistent with the notion that the failure of normal mRNAs to be translated under heat shock conditions might be due, at least to some extent, to the inactivation of polypeptide chain initiation factor(s) involved in the recognition of the mRNA 5”terminal cap structure.