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Transcriptional activity of heat shock factor 1 at 37 degrees C is repressed through phosphorylation on two distinct serine residues by glycogen synthase kinase 3 and protein kinases Calpha and Czeta.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 1998 Jul 17; Vol. 273 (29), pp. 18640-6. - Publication Year :
- 1998
-
Abstract
- Heat shock factor 1 (HSF1) is the key transcriptional regulator of the heat shock genes that protect cells from environmental stress. However, because heat shock gene expression is deleterious to growth and development, we have examined mechanisms for HSF1 repression at growth temperatures, focusing on the role of phosphorylation. Mitogen-activated protein kinases (MAPKs) of the ERK family phosphorylate HSF1 and represses transcriptional function. The mechanism of repression involves initial phosphorylation by MAP kinase on serine 307, which primes HSF1 for secondary phosphorylation by glycogen synthase kinase 3 on a key residue in repression (serine 303). In vivo expression of glycogen synthase kinase 3 alpha or beta thus represses HSF1 through phosphorylation of serine 303. HSF1 is also phosphorylated by MAPK in vitro on a second residue (serine 363) adjacent to activation domain 1, and this residue is additionally phosphorylated by protein kinase C. In vivo, HSF1 is repressed through phosphorylation of this residue by protein kinase Calpha or -zeta but not MAPK. Regulation at 37 degrees C, therefore, involves the action of three protein kinase cascades that repress HSF1 through phosphorylation of serine residues 303, 307, and 363 and may promote growth by suppressing the heat shock response.
- Subjects :
- 3T3 Cells
Animals
Calcium-Calmodulin-Dependent Protein Kinases genetics
Glycogen Synthase Kinase 3
Glycogen Synthase Kinases
Heat Shock Transcription Factors
Mice
Mutagenesis, Site-Directed
Phosphorylation
Protein Kinase C-alpha
Temperature
Calcium-Calmodulin-Dependent Protein Kinases metabolism
DNA-Binding Proteins metabolism
Heat-Shock Proteins metabolism
Isoenzymes metabolism
Protein Kinase C metabolism
Serine metabolism
Transcription Factors metabolism
Transcription, Genetic
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 273
- Issue :
- 29
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 9660838
- Full Text :
- https://doi.org/10.1074/jbc.273.29.18640