Involvement of DNA binding domain in the cellular stability and importin affinity of NF-κB component RelB
| Autor: | Kazuo Umezawa, Daisuke Takahashi, Mariko Watanabe, Ryoichi Horie, Masatoshi Takeiri, Siro Simizu, Kana Horie |
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| Rok vydání: | 2012 |
| Předmět: |
Models
Molecular Molecular Sequence Data Nuclear Localization Signals Importin Karyopherins Arginine Biochemistry Mutant protein Humans Amino Acid Sequence Physical and Theoretical Chemistry Binding site Transcription factor Cellular localization Cell Nucleus Alanine Binding Sites Chemistry Cyclohexanones Protein Stability RELB Organic Chemistry Transcription Factor RelB DNA-binding domain Molecular biology Recombinant Proteins Protein Structure Tertiary Protein Transport Benzamides Mutation Tyrosine Nuclear localization sequence HeLa Cells |
| Zdroj: | Organicbiomolecular chemistry. 10(15) |
| ISSN: | 1477-0539 |
| Popis: | NF-κB is a transcription factor for the immune activation and tissue stability, but excess activation of NF-κB often causes inflammation and cancer. An NF-κB component RelB is involved in B-cell maturation and autoimmunity. In the present research we studied the role of the RelB DNA binding domain on cellular stability and importin affinity. We prepared a RelB protein mutated at Arg141 to Ala and Tyr142 to Ala (AA mutant) having no DNA binding activity. The stability of this mutant protein was greatly reduced compared with that of the wild-type protein. We also constructed a nuclear localization signal-inactivated mutant of RelB, and found that this mutant was also unstable in the cells. Thus, RelB destabilization was caused by the loss of DNA binding possibly because of the change in cellular localization. The mutation also decreased the affinity to importin-α5 decreasing the nuclear localization. Our newly discovered NF-κB inhibitor (−)-DHMEQ binds to a specific Cys residue in RelB to inhibit DNA binding and also decreased the stability and importin affinity. These findings would indicate that the DNA binding activity of this transcription factor is a crucial for its stability and intracellular localization. |
| Databáze: | OpenAIRE |
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