Structural and functional insights into IkappaB-alpha/HIV-1 Tat interaction(751 views) Vitagliano L, Fiume G, Scognamiglio PL, Doti N, Cannavo R, Puca A, Pedone C, Scala G, Quinto I, Marasco D
Keywords: Cd Spectroscopy, Luciferase Assay, Surface Plasmon Resonance, Human Immunodeficiency Virus Proteinase, I Kappa B Alpha, Transactivator Protein, Article, Binding Affinity, Chemical Mutagenesis, Circular Dichroism, Hela Cell, Human Cell, Immunoprecipitation, In Vitro Study, Molecular Recognition, Nonhuman, Protein Binding, Protein Expression, Protein Folding, Protein Immobilization, Protein Protein Interaction, Protein Synthesis, Western Blotting, Amino Acid Sequence, Binding Sites, Cell Nucleus, Hiv-1, I-Kappa B Proteins, Kinetics, Molecular Sequence Data, Nf-Kappa B, Structure-Activity Relationship, Tat Gene Products, Metabolism, Chemistry,
Affiliations: *** IBB - CNR ***
Institute of Biostructures and Bioimaging, CNR, Via Mezzocannone 16, 80134 Naples, Italy.
Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa-Germaneto, 88100 Catanzaro, Italy
Department of Biological Sciences, University Federico II of Naples, Via Mezzocannone 16, 80134 Naples, Italy
Department of Biochemistry and Medical Biotechnology, University Federico II of Naples, Via Sergio Pansini 5, 80131 Naples, Italy
References: Not available.
Structural and functional insights into IkappaB-alpha/HIV-1 Tat interaction
Protein protein interactions play fundamental roles in physiological and pathological biological processes. The characterization of the structural determinants of protein-protein recognition represents an important step for the development of molecular entities able to modulate these interactions. We have recently found that I kappa B-alpha (nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha) blocks the HIV-1 expression and replication in a NF-kappa B-independent manner by directly binding to the virus-encoded Tat transactivator. Here, we report the evaluation of the entity of binding of I kappa B-alpha to Tat through in vitro Surface Plasmon Resonance assay. Moreover, by designing and characterizing a set of peptides of the C-terminus region of I kappa B-alpha, we show that the peptide corresponding to the I kappa B-alpha sequence 262-287 was able to bind to Tat with high affinity (300 nM). The characterization of a number of I kappa B-alpha-based peptides also provided insights into their intrinsic folding properties. These findings have been corroborated by mutagenesis studies on the full-length I kappa B-alpha, which unveil that different I kappa B-alpha residues are involved in NF-kappa B or Tat recognition. (C) 2011 Elsevier Masson SAS. All rights reserved.
Structural and functional insights into IkappaB-alpha/HIV-1 Tat interaction