Structural Basis of Cyclic Nucleotide Selectivity in cGMP-dependent Protein Kinase II

• Published in: The Journal of biological chemistry Vol. 291; no. 11; pp. 5623 - 5633
• Main Authors: Campbell, James C., Kim, Jeong Joo, Li, Kevin Y., Huang, Gilbert Y., Reger, Albert S., Matsuda, Shinya, Sankaran, Banumathi, Link, Todd M., Yuasa, Keizo, Ladbury, John E., Casteel, Darren E., Kim, Choel
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 11-03-2016; American Society for Biochemistry and Molecular Biology
• Subjects: Allosteric Regulation; Animals; BASIC BIOLOGICAL SCIENCES; cGMP-dependent protein kinase; Chlorocebus aethiops; COS Cells; Crystallography, X-Ray; Cyclic AMP - metabolism; Cyclic GMP - metabolism; Cyclic GMP-Dependent Protein Kinase Type II - chemistry; Cyclic GMP-Dependent Protein Kinase Type II - metabolism; cyclic nucleotide; cyclic nucleotide-binding domain (CNB); HEK293 Cells; Humans; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; ligand-binding protein; Models, Molecular; NO-cGMP signaling; protein kinase G (PKG); Protein Structure and Folding; Protein Structure, Tertiary; receptor structure-function; second messenger; serine/threonine protein kinase; Substrate Specificity; X-ray crystallography; ligand-binding protein; X-ray crystallography; cGMP-dependent protein kinase; cyclic nucleotide-binding domain (CNB); serine/threonine protein kinase; allosteric regulation; second messenger; cyclic nucleotide; NO-cGMP signaling; receptor structure-function; protein kinase G (PKG)
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M115.691303

Membrane-bound cGMP-dependent protein kinase (PKG) II is a key regulator of bone growth, renin secretion, and memory formation. Despite its crucial physiological roles, little is known about its cyclic nucleotide selectivity mechanism due to a lack of structural information. Here, we find that the C-terminal cyclic nucleotide binding (CNB-B) domain of PKG II binds cGMP with higher affinity and selectivity when compared with its N-terminal CNB (CNB-A) domain. To understand the structural basis of cGMP selectivity, we solved co-crystal structures of the CNB domains with cyclic nucleotides. Our structures combined with mutagenesis demonstrate that the guanine-specific contacts at Asp-412 and Arg-415 of the αC-helix of CNB-B are crucial for cGMP selectivity and activation of PKG II. Structural comparison with the cGMP selective CNB domains of human PKG I and Plasmodium falciparum PKG (PfPKG) shows different contacts with the guanine moiety, revealing a unique cGMP selectivity mechanism for PKG II.