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

作者：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^*

来源：JOURNAL OF BIOLOGICAL CHEMISTRY, 2016, 291(11): 5623-5633.

DOI：10.1074/jbc.M115.691303

• allosteric regulation
• cyclic nucleotide
• ligand-binding protein
• protein kinase G (PKG)
• receptor structure-function
• serine
• threonine protein kinase
• X-ray crystallography
• NO-cGMP signaling
• cGMP-dependent protein kinase
• cyclic nucleotide-binding domain (CNB)
• second messenger

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 C-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.

• 出版日期2016-3-11