Publications by authors named "Anne Chapelle"

2 Publications

  • Page 1 of 1

The structural and dynamic response of MAGI-1 PDZ1 with noncanonical domain boundaries to the binding of human papillomavirus E6.

J Mol Biol 2011 Mar 13;406(5):745-63. Epub 2011 Jan 13.

Equipe Oncoprotéines, Ecole Supérieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, BP 10413, 67412 Illkirch Cedex, France.

PDZ domains are protein interaction domains that are found in cytoplasmic proteins involved in signaling pathways and subcellular transport. Their roles in the control of cell growth, cell polarity, and cell adhesion in response to cell contact render this family of proteins targets during the development of cancer. Targeting of these network hubs by the oncoprotein E6 of "high-risk" human papillomaviruses (HPVs) serves to effect the efficient disruption of cellular processes. Using NMR, we have solved the three-dimensional solution structure of an extended construct of the second PDZ domain of MAGI-1 (MAGI-1 PDZ1) alone and bound to a peptide derived from the C-terminus of HPV16 E6, and we have characterized the changes in backbone dynamics and hydrogen bonding that occur upon binding. The binding event induces quenching of high-frequency motions in the C-terminal tail of the PDZ domain, which contacts the peptide upstream of the canonical X-[T/S]-X-[L/V] binding motif. Mutations designed in the C-terminal flanking region of the PDZ domain resulted in a significant decrease in binding affinity for E6 peptides. This detailed analysis supports the notion of a global response of the PDZ domain to the binding event, with effects propagated to distal sites, and reveals unexpected roles for the sequences flanking the canonical PDZ domain boundaries.
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http://dx.doi.org/10.1016/j.jmb.2011.01.015DOI Listing
March 2011

Surface plasmon resonance analysis of the binding of high-risk mucosal HPV E6 oncoproteins to the PDZ1 domain of the tight junction protein MAGI-1.

J Mol Recognit 2011 Jul-Aug;24(4):511-23. Epub 2010 Sep 14.

Équipe Oncoprotéines, FRE 3211, Institut de Recherche de l'École de Biotechnologie de Strasbourg, Université de Strasbourg, Boulevard Sébastien Brandt, BP 10413, 67412 Illkirch Cedex, France.

The E6 oncoproteins from high-risk mucosal human papillomavirus (HPV) induce cervical cancer via two major activities, the binding and the degradation of the p53 protein and PDZ domain-containing proteins. Human MAGI-1 is a multi-PDZ domain protein implicated into protein complex assembly at cell-cell contacts. High-risk mucosal HPV E6 proteins interact with the PDZ1 domain of MAGI-1 via a C-terminal consensus binding motif. Here, we developed a medium throughput protocol to accurately measure by surface plasmon resonance affinity constants of protein domains binding to peptidic sequences produced as recombinant fusions to the glutathione-S-transferase (GST). This approach was applied to measure the binding of MAGI-1 PDZ1 to the C-termini of viral or cellular proteins. Both high-risk mucosal HPV E6 C-terminal peptides and cellular partners of MAGI-1 PDZ1 bind to MAGI-1 PDZ1 with comparable dissociation constants in the micromolar range. MAGI-1 PDZ1 shows a preference for C-termini with a valine at position 0 and a negative charge at position -3, confirming previous studies performed with HPV18 E6. A detailed combined analysis via site-directed mutagenesis of the HPV16 C-terminal peptide and PDZ1 indicated that interactions mediated by charged residues upstream the PDZ-binding motif strongly contribute to binding selectivity of this interaction. In addition, our work highlighted the K(499) residue of MAGI-1 as a novel determinant of binding specificity. Finally, we showed that MAGI-1 PDZ1 also binds to the C-termini of LPP and Tax proteins, which were already known to bind to PDZ proteins but not to MAGI-1.
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http://dx.doi.org/10.1002/jmr.1056DOI Listing
September 2011