2004 Fiscal Year Final Research Report Summary
Identification and clinical application of a novel regulatory proteins under hypoxic stress
| Project/Area Number |
15590287
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Pathological medical chemistry
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| Research Institution | TOKYO MRTROPOLITAN ORGANIZATION FOR MEDICAL RESEARCH |
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Principal Investigator |
KATO Hiroyuki Tokyo Metropolitan Institute of Medical Science, researcher, 東京都臨床医学総合研究所, 研究員 (30301732)
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| Co-Investigator(Kenkyū-buntansha) |
SHIBASAKI Futoshi Tokyo Metropolitan Institute of Medical Science, Dept.of Molecular Cell physiology, chief researcher, 副参事研究員 (90300954)
HOSHINO Makoto Tokyo Metropolitan Institute of Medical Science, Dept.of Molecular Cell physiology, researcher, 研究員 (40212196)
KATO Hiroyuki Tokyo Metropolitan Institute of Medical Science, Dept.of Molecular Cell physiology, Researcher (30301732)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Hypoxia / Histone deacetylase / nuclear import / nuclear export / Yeast two-hybrid system / re-oxygenation |
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| Research Abstract |
Hypoxia-inducible factor (HIF)-1α is a transcription factor that controls expression of genes responsive to low oxygen tension, including vascular endothelial growth factor, erythropoien, and glycolytic enzymes. The activation of HIF-1a is regulated by binding to the transcriptional co-activator cAMP response element-binding protein-binding protein (CBP)/p300. Using the yeast two-hybrid screening system, we found that the inhibitory domain of HIF-1α strongly interacted with the C-terminal domain of histone deacetylase (HDAC)7. The o-nitrophenyl β-D-galactopyranoside assay revealed that regions containing amino acids 735-785 of HIF-1α and amino acids 669-952 of HDAC7 were minimum contact sites of the interaction. The binding of HDAC7 with HIF-1α was reproduced in HEK293 cells grown under normoxic and hypoxic condition (2%, O2). HDAC7 bound solely to HIF-1α among other HIF-α family members, including HIF-2α and HIF-3α, whereas HIF-1α only interacted with HDAC7 in the class HDAC family. Although HDAC7 was localized dominantly in the cytoplasm at normal oxygen concentrations, In the nucleus, HDAC7 increased transcriptional activity of HIF-1α through the formation of a complex with HIF-1α, HDAC7 and p300. Token together, these results indicated that HDAC7 is a novel transcriptional activator of HIF-1α. Currently we found that disscociation of HDAC7 from HDAC7/HIF-1α complex and the export of HDAC7 to the cytoplasm regulated HIF-1α degradation upon the transition from hypoxic oxygen condition to normal oxygen condition (re-oxygenation).
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