title: Photolabeling study of the ligand binding domain of natriuretic peptide receptor A: development of a model.
abstract: Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are loop-shaped peptidic hormones that have multiple actions on body fluid homeostasis. Their physiological effects are mediated through the activation of their receptor, natriuretic peptide receptor A (NPRA). This receptor is a member of the membrane guanylyl cyclase family and catalyzes cyclic guanosine monophosphate (cGMP) production following its activation. To map the binding site of human NPRA, we applied the methionine proximity assay method to this receptor. We photolabeled NPRA mutants, presenting a single methionine in the binding domain of the receptor, and used benzoylphenylalanine- (Bpa-) substituted peptides at positions 0, 3, 18, 26, and 28 of the ligand. We identified that the N-terminus of the peptide is interacting with the region between Asp(177) and Val(183) of the receptor. Arg(3) is interacting in the vicinity of Phe(172). Leu(18) binds close to Val(116). Phe(26) binds in the vicinity of His(195), and the C-terminal Tyr(28) is located close to Met(173). We next proceeded with photolabeling of a dual Bpa-substituted peptide and showed that the N-terminus and Leu(18) interact with opposite receptor subunits. On the basis of our results, a molecular model of peptide-bound NPRA was developed by homology modeling with the C-type natriuretic peptide- (CNP-) bound natriuretic peptide receptor C (NPRC) crystal structure. The model has been validated by molecular dynamics simulations. Our work provides a rational basis for interpreting and predicting natriuretic peptide binding to the human NPRA.
authors.affiliation: Département de Pharmacologie, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Jossart
authors.forename: Martin
authors.initials: M
authors.lastname: Coupal
authors.forename: Normand
authors.initials: N
authors.lastname: McNicoll
authors.forename: Alain
authors.initials: A
authors.lastname: Fournier
authors.forename: Brian C
authors.initials: BC
authors.lastname: Wilkes
authors.forename: André
authors.initials: A
authors.lastname: De Léan
mesh_terms: D000595:Amino Acid Sequence; D001120:Arginine / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D006162:Guanylate Cyclase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006639:Histidine / Q000378:metabolism; D006801:Humans; D007930:Leucine / Q000378:metabolism; D008024:Ligands; D008715:Methionine / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D020097:Natriuretic Peptide, Brain / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism; D019920:Photoaffinity Labels / Q000138:chemical synthesis / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000235:genetics; D021122:Protein Subunits / Q000378:metabolism; D017461:Receptors, Atrial Natriuretic Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013816:Thermodynamics; D014443:Tyrosine / Q000378:metabolism; D014633:Valine / Q000378:metabolism
chemical_list: D008024:Ligands; D010446:Peptide Fragments; D019920:Photoaffinity Labels; D021122:Protein Subunits; D020097:Natriuretic Peptide, Brain; D014443:Tyrosine; D010649:Phenylalanine; D006639:Histidine; D001120:Arginine; D008715:Methionine; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor; C091715:atrial natriuretic factor receptor A; D007930:Leucine; D014633:Valine