Regulation of heat shock factor trimer formation: role of a conserved leucine zipper.
The human and Drosophila heat shock transcription factors (HSFs) are multi-zipper proteins with high-affinity binding to DNA that is regulated by heat shock-induced trimerization. Formation of HSF trimers is dependent on hydrophobic heptad repeats located in the amino-terminal region of the protein. Two subregions at the carboxyl-terminal end of human HSF1 were identified that maintain the monomeric form of the protein under normal conditions. One of these contains a leucine zipper motif that is conserved between vertebrate and insect HSFs. These results suggest that the carboxyl-terminal zipper may suppress formation of trimers by the amino-terminal HSF zipper elements by means of intramolecular coiled-coil interactions that are sensitive to heat shock.
Rabindran
S K
SK
Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Haroun
R I
RI
Clos
J
J
Wisniewski
J
J
Wu
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D004330:Drosophila / Q000737:chemistry; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D016350:Leucine Zippers; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016296:Mutagenesis; D013329:Structure-Activity Relationship; D014162:Transfection
D006360:Heat-Shock Proteins; D046911:Macromolecular Substances; D004247:DNA