dc.creator | Mylonis, I. | en |
dc.creator | Chachami, G. | en |
dc.creator | Samiotaki, M. | en |
dc.creator | Panayotou, G. | en |
dc.creator | Paraskeva, E. | en |
dc.creator | Kalousi, A. | en |
dc.creator | Georgatsou, E. | en |
dc.creator | Bonanou, S. | en |
dc.creator | Simos, G. | en |
dc.date.accessioned | 2015-11-23T10:40:20Z | |
dc.date.available | 2015-11-23T10:40:20Z | |
dc.date.issued | 2006 | |
dc.identifier | 10.1074/jbc.M605058200 | |
dc.identifier.issn | 219258 | |
dc.identifier.uri | http://hdl.handle.net/11615/31241 | |
dc.description.abstract | Hypoxia-inducible factor 1 (HIF-1) controls the expression of most genes induced by hypoxic conditions. Regulation of expression and activity of its inducible subunit, HIF-1α, involves several post-translational modifications. To study HIF-1α phosphorylation, we have used human full-length recombinant HIF-1α as a substrate in kinase assays. We show that at least two different nuclear protein kinases, one of them identified as p42/p44 MAPK, can modify HIF-1α. Analysis of in vitro phosphorylated HIF-1α by mass spectroscopy revealed residues Ser-641 and Ser-643 as possible MAPK phosphorylation sites. Site-directed mutagenesis of these residues reduced significantly the phosphorylation of HIF-1α. When these mutant forms of HIF-1α were expressed in HeLa cells, they exhibited much lower transcriptional activity than the wild-type form. However, expression of the same mutants in yeast revealed that their capacity to stimulate transcription was not significantly compromised. Localization of the green fluorescent protein-tagged HIF-1α mutants in HeLa cells showed their exclusion from the nucleus in contrast to wild-type HIF-1α. Treatment of the cells with leptomycin B, an inhibitor of the major exportinCRM1,reversed this exclusion and led to nuclear accumulation and partial recovery of the activity of the HIF-1α mutants. Moreover, inhibition of the MAPK pathway by PD98059 impaired the phosphorylation, nuclear accumulation, and activity of wild-type GFP-HIF-1α. Overall, these data suggest that phosphorylation of Ser-641/643 by MAPK promotes the nuclear accumulation and transcriptional activity of HIF-1α by blocking its CRM1-dependent nuclear export. © 2006 by The American Society for Biochemistry and Molecular Biology, Inc. | en |
dc.source.uri | http://www.scopus.com/inward/record.url?eid=2-s2.0-33845403070&partnerID=40&md5=f034cf03f6da3dee744e9ce6032a5d84 | |
dc.subject | Activation analysis | en |
dc.subject | Bioassay | en |
dc.subject | Enzymes | en |
dc.subject | Mass spectrometers | en |
dc.subject | Mutagenesis | en |
dc.subject | Substrates | en |
dc.subject | Green fluorescent protein | en |
dc.subject | Hypoxic conditions | en |
dc.subject | Mutants | en |
dc.subject | Nuclear protein kinases | en |
dc.subject | Genes | en |
dc.subject | 2 (2 amino 3 methoxyphenyl)chromone | en |
dc.subject | hybrid protein | en |
dc.subject | hypoxia inducible factor 1alpha | en |
dc.subject | leptomycin B | en |
dc.subject | mitogen activated protein kinase | en |
dc.subject | protein kinase | en |
dc.subject | protein p300 | en |
dc.subject | protein p42 | en |
dc.subject | protein p44 | en |
dc.subject | serine | en |
dc.subject | article | en |
dc.subject | controlled study | en |
dc.subject | enzyme phosphorylation | en |
dc.subject | fluorescence microscopy | en |
dc.subject | gene expression regulation | en |
dc.subject | HeLa cell | en |
dc.subject | human | en |
dc.subject | human cell | en |
dc.subject | hypoxia | en |
dc.subject | immunoprecipitation | en |
dc.subject | in vitro study | en |
dc.subject | mass spectrometry | en |
dc.subject | plasmid | en |
dc.subject | polyacrylamide gel electrophoresis | en |
dc.subject | priority journal | en |
dc.subject | protein processing | en |
dc.subject | protein purification | en |
dc.subject | site directed mutagenesis | en |
dc.subject | Western blotting | en |
dc.subject | Amino Acid Sequence | en |
dc.subject | Animals | en |
dc.subject | Cell Nucleus | en |
dc.subject | Hela Cells | en |
dc.subject | Humans | en |
dc.subject | Hypoxia-Inducible Factor 1, alpha Subunit | en |
dc.subject | Mitogen-Activated Protein Kinase 1 | en |
dc.subject | Mitogen-Activated Protein Kinase 3 | en |
dc.subject | Molecular Sequence Data | en |
dc.subject | Phosphorylation | en |
dc.subject | Phosphoserine | en |
dc.subject | Sequence Alignment | en |
dc.subject | Trans-Activation (Genetics) | en |
dc.subject | Transcription, Genetic | en |
dc.title | Identification of MAPK phosphorylation sites and their role in the localization and activity of hypoxia-inducible factor-1α | en |
dc.type | journalArticle | en |