title: Dysfunctional conformational dynamics of protein kinase A induced by a lethal mutant of phospholamban hinder phosphorylation.
abstract: The dynamic interplay between kinases and substrates is crucial for the formation of catalytically committed complexes that enable phosphoryl transfer. However, a clear understanding on how substrates modulate kinase structural dynamics to control catalytic efficiency is still missing. Here, we used solution NMR spectroscopy to study the conformational dynamics of two complexes of the catalytic subunit of the cAMP-dependent protein kinase A with WT and R14 deletion phospholamban, a lethal human mutant linked to familial dilated cardiomyopathy. Phospholamban is a central regulator of heart muscle contractility, and its phosphorylation by protein kinase A constitutes a primary response to β-adrenergic stimulation. We found that the single deletion of arginine in phospholamban's recognition sequence for the kinase reduces its binding affinity and dramatically reduces phosphorylation kinetics. Structurally, the mutant prevents the enzyme from adopting conformations and motions committed for catalysis, with concomitant reduction in catalytic efficiency. Overall, these results underscore the importance of a well-tuned structural and dynamic interplay between the kinase and its substrates to achieve physiological phosphorylation levels for proper Ca(2+) signaling and normal cardiac function.
authors.affiliation: Departments of Chemistry and.
authors.forename: Jonggul
authors.initials: J
authors.lastname: Kim
authors.affiliation: Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455;
authors.forename: Larry R
authors.initials: LR
authors.lastname: Masterson
authors.affiliation: Departments of Chemistry and Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455;
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cembran
authors.affiliation: Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455;
authors.forename: Raffaello
authors.initials: R
authors.lastname: Verardi
authors.affiliation: Departments of Chemistry and.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.affiliation: Departments of Chemistry and Theoretical Chemistry Institute, Jilin University, Changchun 130028, People's Republic of China; and.
authors.forename: Jiali
authors.initials: J
authors.lastname: Gao
authors.affiliation: Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093 staylor@ucsd.edu vegli001@umn.edu.
authors.forename: Susan S
authors.initials: SS
authors.lastname: Taylor
authors.affiliation: Departments of Chemistry and Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455; staylor@ucsd.edu vegli001@umn.edu.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Veglia
mesh_terms: D000495:Allosteric Site; D000595:Amino Acid Sequence; D002118:Calcium / Q000737:chemistry; D002135:Calcium-Binding Proteins / Q000737:chemistry*; D000252:Calcium-Transporting ATPases / Q000737:chemistry; D002311:Cardiomyopathy, Dilated / Q000235:genetics; D020134:Catalytic Domain; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry*; D018450:Disease Progression; D017353:Gene Deletion; D006801:Humans; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D009154:Mutation; D009206:Myocardium / Q000201:enzymology; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013816:Thermodynamics; D000099211:Phospholamban
chemical_list: D002118:Calcium; D002135:Calcium-Binding Proteins; D000252:Calcium-Transporting ATPases; D017868:Cyclic AMP-Dependent Protein Kinases; D008024:Ligands; D000099211:Phospholamban
keywords: NMR; calcium regulation; conformational dynamics; phospholamban; phosphorylation