h-sgk serine-threonine protein kinase as transcriptional target of p38/MAP kinase pathway in HepG2 human hepatoma cells

S Waldegger, S Gabrysch, P Barth, S Fillon… - Cellular Physiology and …, 2000 - karger.com
S Waldegger, S Gabrysch, P Barth, S Fillon, F Lang
Cellular Physiology and Biochemistry, 2000karger.com
The human serum and glucocorticoid dependent serine/threonine kinase h-sgk has
previously been discovered as cell volume regulated gene. The present study has been
performed to elucidate the involvement of p38-kinase in the transcriptional control of h-sgk
by osmotic cell shrinkage. The p38-kinase has previously been cloned as the mammalian
homologue of HOG1 kinase, which constitutes a part of the osmosensor in the yeast
Saccharomyces cerevisiae. Phosphorylated (active) p38-kinase has been estimated with …
Abstract
The human serum and glucocorticoid dependent serine/threonine kinase h-sgk has previously been discovered as cell volume regulated gene. The present study has been performed to elucidate the involvement of p38-kinase in the transcriptional control of h-sgk by osmotic cell shrinkage. The p38-kinase has previously been cloned as the mammalian homologue of HOG1 kinase, which constitutes a part of the osmosensor in the yeast Saccharomyces cerevisiae. Phosphorylated (active) p38-kinase has been estimated with Western blotting, transcription of hsgk using Northern blotting. Both, increase of extracellular NaCl concentration by 50 mmol/l and addition of 10 μmol/l anisomycin increase phosphorylation of the p38-kinase within 5 to 10 minutes. h-sgk transcription is upregulated by addition of 50 mmol/l NaCl and by anisomycin (10 μmol/l), effects completely inhibited by the specific p38-kinase inhibitor, SB 203580 (10 μmol/l). In conclusion, the stimulation of h-sgk transcription by osmotic cell shrinkage is mediated by p38-kinase.
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