» Articles » PMID: 28793191

Structural Basis of Analog Specificity in PKG I and II

Overview
Journal ACS Chem Biol
Specialties Biochemistry
Biology
Date 2017 Aug 10
PMID 28793191
Citations 6
Authors
Affiliations
Soon will be listed here.
Abstract

Cyclic GMP analogs, 8-Br, 8-pCPT, and PET-cGMP, have been widely used for characterizing cellular functions of cGMP-dependent protein kinase (PKG) I and II isotypes. However, interpreting results obtained using these analogs has been difficult due to their low isotype specificity. Additionally, each isotype has two binding sites with different cGMP affinities and analog selectivities, making understanding the molecular basis for isotype specificity of these compounds even more challenging. To determine isotype specificity of cGMP analogs and their structural basis, we generated the full-length regulatory domains of PKG I and II isotypes with each binding site disabled, determined their affinities for these analogs, and obtained cocrystal structures of both isotypes bound with cGMP analogs. Our affinity and activation measurements show that PET-cGMP is most selective for PKG I, whereas 8-pCPT-cGMP is most selective for PKG II. Our structures of cyclic nucleotide binding (CNB) domains reveal that the B site of PKG I is more open and forms a unique π/π interaction through Arg285 at β4 with the PET moiety, whereas the A site of PKG II has a larger β5/β6 pocket that can better accommodate the bulky 8-pCPT moiety. Our structural and functional results explain the selectivity of these analogs for each PKG isotype and provide a starting point for the rational design of isotype selective activators.

Citing Articles

Identifying therapeutic drug targets using bidirectional effect genes.

Estrada K, Froelich S, Wuster A, Bauer C, Sterling T, Clark W Nat Commun. 2021; 12(1):2224.

PMID: 33850126 PMC: 8044152. DOI: 10.1038/s41467-021-21843-8.


Cyclic nucleotide selectivity of protein kinase G isozymes.

Kim C, Sharma R Protein Sci. 2020; 30(2):316-327.

PMID: 33271627 PMC: 7784742. DOI: 10.1002/pro.4008.


Structural basis for selective inhibition of human PKG Iα by the balanol-like compound N46.

Qin L, Sankaran B, Aminzai S, Casteel D, Kim C J Biol Chem. 2018; 293(28):10985-10992.

PMID: 29769318 PMC: 6052212. DOI: 10.1074/jbc.RA118.002427.


Neutron Crystallography Detects Differences in Protein Dynamics: Structure of the PKG II Cyclic Nucleotide Binding Domain in Complex with an Activator.

Gerlits O, Campbell J, Blakeley M, Kim C, Kovalevsky A Biochemistry. 2018; 57(12):1833-1837.

PMID: 29517905 PMC: 5890435. DOI: 10.1021/acs.biochem.8b00010.


New cGMP analogues restrain proliferation and migration of melanoma cells.

Vighi E, Rentsch A, Henning P, Comitato A, Hoffmann D, Bertinetti D Oncotarget. 2018; 9(4):5301-5320.

PMID: 29435180 PMC: 5797051. DOI: 10.18632/oncotarget.23685.


References
1.
Qin L, Reger A, Guo E, Yang M, Zwart P, Casteel D . Structures of cGMP-Dependent Protein Kinase (PKG) Iα Leucine Zippers Reveal an Interchain Disulfide Bond Important for Dimer Stability. Biochemistry. 2015; 54(29):4419-22. PMC: 4838416. DOI: 10.1021/acs.biochem.5b00572. View

2.
Schlossmann J, Hofmann F . cGMP-dependent protein kinases in drug discovery. Drug Discov Today. 2005; 10(9):627-34. DOI: 10.1016/S1359-6446(05)03406-9. View

3.
Valtcheva N, Nestorov P, Beck A, Russwurm M, Hillenbrand M, Weinmeister P . The commonly used cGMP-dependent protein kinase type I (cGKI) inhibitor Rp-8-Br-PET-cGMPS can activate cGKI in vitro and in intact cells. J Biol Chem. 2008; 284(1):556-562. DOI: 10.1074/jbc.M806161200. View

4.
Rehmann H, Wittinghofer A, Bos J . Capturing cyclic nucleotides in action: snapshots from crystallographic studies. Nat Rev Mol Cell Biol. 2006; 8(1):63-73. DOI: 10.1038/nrm2082. View

5.
Casteel D, Smith-Nguyen E, Sankaran B, Roh S, Pilz R, Kim C . A crystal structure of the cyclic GMP-dependent protein kinase I{beta} dimerization/docking domain reveals molecular details of isoform-specific anchoring. J Biol Chem. 2010; 285(43):32684-32688. PMC: 2963381. DOI: 10.1074/jbc.C110.161430. View