The protein kinase inhibitor, H-7, suppresses heat induced activation of heat shock transcription factor 1.
We investigated the effects of a protein kinase (PK) inhibitor, H-7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride), on the regulation of heat shock protein (hsp)72 gene expression in a human glioblastoma cell line (A-172) using a gel mobility-shift assay and Western blot analysis. Heat shock transcription factor 1 (HSF1) was phosphorylated immediately after heat treatment (44 degrees C, 30 min) and the phosphorylation of HSF1 was suppressed by H-7. The increase in DNA binding ability of HSFI to heat shock element (HSE) by heat shock was significantly suppressed by the addition of H-7 in a dose-dependent manner. Similarly, the accumulation of hsp72 by heat shock was suppressed by the addition of H-7 in a dose-dependent manner. Since H-7 is known to be a potent inhibitor of some PKs, especially calcium-dependent PK (PKC), cyclicAMP-dependent PK (PKA) and cyclicGMP-dependent PK (PKG), it is possible that the activation of HSF1 by phosphorylation and subsequent hsp72 gene expression are dependent on some of those PKs. The nature of H-7 as a non-specific inhibitor for PKs is discussed in relation to its availability for regulation of heat sensitivity of cells depending on cellular level of hsp72.
Ohnishi
K
K
Department of Biology, Nara Medical University, Kashihara, Japan.
Wang
X
X
Takahashi
A
A
Matsumoto
H
H
Ohnishi
T
T
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology*; D001483:Base Sequence; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D007700:Kinetics; D047428:Protein Kinase Inhibitors; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; C000619706:HSF1 protein, human; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D047428:Protein Kinase Inhibitors; D014157:Transcription Factors; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine