Structural basis of the Na+/H+ exchanger regulatory factor PDZ1 interaction with the carboxyl-terminal region of the cystic fibrosis transmembrane conductance regulator.
The PDZ1 domain of the Na(+)/H(+) exchanger regulatory factor (NHERF) binds with nanomolar affinity to the carboxyl-terminal sequence QDTRL of the cystic fibrosis transmembrane conductance regulator (CFTR) and plays a central role in the cellular localization and physiological regulation of this chloride channel ...
The PDZ1 domain of the Na(+)/H(+) exchanger regulatory factor (NHERF) binds with nanomolar affinity to the carboxyl-terminal sequence QDTRL of the cystic fibrosis transmembrane conductance regulator (CFTR) and plays a central role in the cellular localization and physiological regulation of this chloride channel. The crystal structure of human NHERF PDZ1 bound to the carboxyl-terminal peptide QDTRL has been determined at 1.7-A resolution. The structure reveals the specificity and affinity determinants of the PDZ1-CFTR interaction and provides insights into carboxyl-terminal leucine recognition by class I PDZ domains. The peptide ligand inserts into the PDZ1 binding pocket forming an additional antiparallel beta-strand to the PDZ1 beta-sheet, and an extensive network of hydrogen bonds and hydrophobic interactions stabilize the complex. Remarkably, the guanido group of arginine at position -1 of the CFTR peptide forms two salt bridges and two hydrogen bonds with PDZ1 residues Glu(43) and Asn(22), respectively, providing the structural basis for the contribution of the penultimate amino acid of the peptide ligand to the affinity of the interaction.
Related Citations:
Crystal Structure of the PDZ1 Domain of Human Na+/H+ Exchanger Regulatory Factor Provides Insights into the Mechanism of Carboxyl-terminal Leucine Recognition by Class I PDZ Domains Karthikeyan, S., Leung, T., Birrane, G., Webster, G., Ladias, J.A.A. (2001) J Mol Biol 308: 963
NHE-RF, A Regulatory Cofactor for NA(+)-H+ Exchange, is a Common Interactor for Merlin and ERM (MERM) Proteins Murthy, A., Gonzalez-Agosti, C., Cordero, E., Pinney, D., Candia, C., Solomon, F., Gusella, J., Ramesh, V. (1998) J Biol Chem 273: 1273
Peptide Binding Consensus of the NHE-RF-PDZ1 Domain Matches the C-terminal Sequence of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Wang, S., W Raab, R., Schatz, P.J., Guggino, W.B., Li, M. (1998) FEBS Lett 427: 103
A C-terminal Motif Found in the Beta2-Adrenergic Receptor, P2Y1 Receptor and Cystic Fibrosis Transmembrane Conductance Regulator Determines Binding to the Na+/H+ Exchanger Regulatory Factor Family of PDZ Proteins Hall, R.A., Ostedgaard, L.S., Premont, R.T., Blitzer, J.T., Rahman, N., Welsh, M.J., Lefkowitz, R.J. (1998) Proc Natl Acad Sci U S A 95: 8496
Organizational Affiliation:
Molecular Medicine Laboratory and Macromolecular Crystallography Unit, Division of Experimental Medicine, Harvard Institutes of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA.
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