Loss of Hsp70 in Drosophila is pleiotropic, with effects on thermotolerance, recovery from heat shock and neurodegeneration.
The heat-shock response is a programmed change in gene expression carried out by cells in response to environmental stress, such as heat. This response is universal and is characterized by the synthesis of a small group of conserved protein chaperones. In Drosophila melanogaster the Hsp70 chaperone dominates the profile of protein synthesis during the heat-shock response. We recently generated precise deletion alleles of the Hsp70 genes of D. melanogaster and have used those alleles to characterize the phenotypes of Hsp70-deficient flies. Flies with Hsp70 deletions have reduced thermotolerance. We find that Hsp70 is essential to survive a severe heat shock, but is not required to survive a milder heat shock, indicating that a significant degree of thermotolerance remains in the absence of Hsp70. However, flies without Hsp70 have a lengthened heat-shock response and an extended developmental delay after a non-lethal heat shock, indicating Hsp70 has an important role in recovery from stress, even at lower temperatures. Lack of Hsp70 also confers enhanced sensitivity to a temperature-sensitive lethal mutation and to the neurodegenerative effects produced by expression of a human polyglutamine disease protein.
Gong
Wei J
WJ
Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA.
Golic
Kent G
KG
D000483:Alleles; D000818:Animals; D030801:Animals, Genetically Modified; D000067699:Ataxin-3; D004331:Drosophila melanogaster / Q000254:growth & development / Q000378:metabolism*; D005804:Genes, Lethal; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D018869:Heat-Shock Response / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D009154:Mutation; D009410:Nerve Degeneration; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins; D012097:Repressor Proteins; D017384:Sequence Deletion; D014162:Transfection
D018840:HSP70 Heat-Shock Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C092341:ATXN3 protein, human; D000067699:Ataxin-3