Analysis of the phosphorylation of human heat shock transcription factor-1 by MAP kinase family members.
The activation of heat shock transcription factor-1 (HSF-1) after treatment of mammalian cells with stresses such as heat shock, heavy metals, or ethanol induces the synthesis of heat shock proteins. HSF-1 is phosphorylated at normal growth temperature and is hyperphosphorylated upon stress. We recently presented evidence that HSF-1 can be phosphorylated by the mitogen activated protein kinase, ERK1, and that such phosphorylation appears to negatively regulate the activity of HSF-1. In this report, we have tested the ability of ERK1 to phosphorylate various HSF-1 deletion mutants. Our results show that ERK1 phosphorylation is dependent on a region of HSF-1 extending from amino acids 280 to 308. This region contains three serine residues that are potential ERK1 phosphorylation sites. The region falls within a previously defined regulatory domain of HSF-1. The possibility of protein kinases other than ERK1 phosphorylating HSF-1 was also examined using in-gel kinase assays. The results show that HSF-1 can be phosphorylated in a ras-dependent manner by other members of the MAP kinase family such as JNK and p38 protein kinases and possibly others.
Kim
J
J
Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta 30912, USA.
Nueda
A
A
Meng
Y H
YH
Dynan
W S
WS
Mivechi
N F
NF
D016475:3T3 Cells; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018869:Heat-Shock Response; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D051379:Mice; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D010766:Phosphorylation; D011993:Recombinant Fusion Proteins; D017384:Sequence Deletion; D012694:Serine / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases; D018631:ras Proteins / Q000502:physiology
D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D012694:Serine; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D018631:ras Proteins