biostudies-literatureCampbell JCHoward Hughes Medical InstituteNIGMS NIH HHS5623-33https://www.ebi.ac.uk/biostudies/studies/S-EPMC4786703biostudies-literatureUnknown291(11)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.The Journal of biological chemistryStructural Basis of Cyclic Nucleotide Selectivity in cGMP-dependent Protein Kinase II.PMC4786703T32 GM089657R01 GM090161R25 GM0569292R01GM090161T32GM008280T32 GM008280Campbell JCYuasa KKim CKim JJHuang GYMatsuda SLink TMLadbury JEReger ASLi KYSankaran BCasteel DEfalseStructural Basis of Cyclic Nucleotide Selectivity in cGMP-dependent Protein Kinase II.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.2016-01-01T00:00:00Z2016 Mar2020-11-19T14:47:09Z2019-03-27T02:10:53ZS-EPMC47867032676996410.1074/jbc.m115.69130310.1074/jbc.M115.691303