Adenovirus E1A N-Terminal Amino Acid Sequence Requirements for Repression of Transcription In Vitro and In Vivo Correlate with Those Required for E1A Interference with TBP-TATA Complex Formation
| Autor: | Janice M. Boyd, Maurice Green, Qing-quan Tang, Paul M. Loewenstein, Li Yu |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: |
Transcription
Genetic TATA box Recombinant Fusion Proteins Immunology Biology Microbiology Structure-Activity Relationship Transcription (biology) Virology Tumor Cells Cultured Humans CREB-binding protein Amino Acids Psychological repression Peptide sequence Transcription factor chemistry.chemical_classification Binding Sites TATA-Box Binding Protein Adenoviruses Human Nuclear Proteins CREB-Binding Protein TATA Box Amino acid Virus-Cell Interactions DNA-Binding Proteins Repressor Proteins chemistry Biochemistry Gene Expression Regulation Insect Science biology.protein Trans-Activators Adenovirus E1A Proteins Peptides Transcription Factors |
| Popis: | The adenovirus (Ad) E1A 243R oncoprotein encodes an N-terminal transcription repression domain that is essential for early viral functions, cell immortalization, and cell transformation. The transcription repression function requires sequences within amino acids 1 to 30 and 48 to 60. To elucidate the roles of the TATA-binding protein (TBP), p300, and the CREB-binding protein (CBP) in the mechanism(s) of E1A repression, we have constructed 29 amino acid substitution mutants and 5 deletion mutants spanning the first 30 amino acids within the E1A 1-80 polypeptide backbone. These mutant E1A polypeptides were characterized with regard to six parameters: the ability to repress transcription in vitro and in vivo, to disrupt TBP-TATA box interaction, and to bind TBP, p300, and CBP. Two regions within E1A residues 1 to 30, amino acids 2 to 6 and amino acid 20, are critical for E1A transcription repression in vitro and in vivo and for the ability to interfere with TBP-TATA interaction. Replacement of 6Cys with Ala in the first region yields the most defective mutant. Replacement of 20Leu with Ala, but not substitutions in flanking residues, yields a substantially defective phenotype. Protein binding assays demonstrate that replacement of 6Cys with Ala yields a mutant completely defective in interaction with TBP, p300, and CBP. Our findings are consistent with a model in which the E1A repression function involves interaction of E1A with p300/CBP and interference with the formation of a TBP-TATA box complex. |
| Databáze: | OpenAIRE |
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