Induction temperature of human heat shock factor is reprogrammed in a Drosophila cell environment.
Heat shock factor (HSF), the transcriptional activator of eukaryotic heat shock genes, is induced to bind DNA by a monomer to trimer transition involving leucine zipper interactions. Although this mode of regulation is shared among many eukaryotic species, there is variation in the temperature at which HSF binding activity is induced. We investigated the basis of this variation by analysing the response of a human HSF expressed in Drosophila cells and Drosophila HSF expressed in human cells. We report here that the temperature that induces DNA binding and trimerization of human HSF in Drosophila was decreased by approximately 10 degrees C to the induction temperature for the host cell, whereas Drosophila HSF expressed in human cells was constitutively active. The results indicate that the activity of HSF in vivo is not a simple function of the absolute environmental temperature.
Clos
J
J
Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Rabindran
S
S
Wisniewski
J
J
Wu
C
C
D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D003001:Cloning, Molecular; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004330:Drosophila; D000076249:Heat Shock Transcription Factors; D006801:Humans; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins / Q000378:metabolism; D013696:Temperature; D014157:Transcription Factors; D014162:Transfection
D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; D011994:Recombinant Proteins; D014157:Transcription Factors; D004247:DNA; D003513:Cycloheximide