The soluble guanylyl cyclase (sGC) is a key signaling protein that stimulates the production of the second messenger cGMP when activated by nitric oxide. This cGMP signaling pathway is important for a number of cardiovascular processes including blood pressure regulation and sGC has therefore attracted considerable attention as a pharmaceutical drug target to treat cardiovascular diseases such as hypertension, heart failure, atherosclerosis, erectile dysfunction, thrombosis, and renal fibrosis. Several compounds targeting sGC are in pre-clinical or clinical trial stages. The applicant has aided the structural understanding of guanylyl cyclases by determining crystal structures of 4 different domains including complexes with the sGC activators BAY 58-2667 and nitric oxide. The overarching goal of this application is to further unravel the signaling intricacies of sGC that could yield insights into how to either utilize or bypass this signaling mechanism such that this information can be pharmaceutically exploited to modulate sGC. The proposed research is of a highly collaborative and multi-disciplinary nature involving techniques such as X-ray crystallography, electron paramagnetic resonance (EPR), isothermal calorimetry (ITC), mutagenesis, and cell biology/activity measurements. The 3 Specific Aims are:
Specific Aim 1 : To test the hypothesis that the activation of the H-NOX domain of sGC involves a partial distortion of the heme pocket. The activation by sGC activators will also be probed for comparison and to delineate the mode of action of these heme mimetics.
Specific Aim 2 : To test the hypothesis that the coiled-coiled (CC) domain of sGC is a parallel dimer and that this domain is not static and undergoes conformational changes during the activation process.
Specific Aim 3 : To test the hypothesis that the N-terminal half of sGC is responsible for binding sets of chemically distinct sGC stimulators;this sGC region includes the H-NOX and PAS/H-NOXA domain(s). The proposed research will lead to new molecular insights into how sGC functions and how GC activators/modulators work and this will enhance our understanding of cardiovascular processes and could lead to the development of new drugs to treat cardiovascular diseases.

Public Health Relevance

Guanylyl cyclases receptors are important receptors involved in a number of cardiovascular processes. The overarching goal of this application is to unravel the molecular signaling details of the soluble guanylyl cyclase activation and its modulation by activators and stimulators. The proposed research will enhance our understanding of cardiovascular processes and could lead to the development of new drugs to treat cardiovascular diseases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL075329-07
Application #
8443849
Study Section
Molecular and Integrative Signal Transduction Study Section (MIST)
Program Officer
OH, Youngsuk
Project Start
2003-12-01
Project End
2015-03-31
Budget Start
2013-04-01
Budget End
2014-03-31
Support Year
7
Fiscal Year
2013
Total Cost
$373,660
Indirect Cost
$135,660
Name
Case Western Reserve University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Kumar, Vijay; Martin, Faye; Hahn, Michael G et al. (2013) Insights into BAY 60-2770 Activation and S-Nitrosylation-Dependent Desensitization of Soluble Guanylyl Cyclase via Crystal Structures of Homologous Nostoc H-NOX Domain Complexes. Biochemistry :
von Wantoch Rekowski, Margarete; Kumar, Vijay; Zhou, Zongmin et al. (2013) Insights into soluble guanylyl cyclase activation derived from improved heme-mimetics. J Med Chem 56:8948-52
Baskaran, Padmamalini; Heckler, Erin J; van den Akker, Focco et al. (2011) Aspartate 102 in the heme domain of soluble guanylyl cyclase has a key role in NO activation. Biochemistry 50:4291-7
Baskaran, Padmamalini; Heckler, Erin J; van den Akker, Focco et al. (2011) Identification of residues in the heme domain of soluble guanylyl cyclase that are important for basal and stimulated catalytic activity. PLoS One 6:e26976
Ma, Xiaolei; Beuve, Annie; van den Akker, Focco (2010) Crystal structure of the signaling helix coiled-coil domain of the beta1 subunit of the soluble guanylyl cyclase. BMC Struct Biol 10:2
Tsai, Ah-Lim; Berka, Vladimir; Martin, Faye et al. (2010) Is Nostoc H-NOX a NO sensor or redox switch? Biochemistry 49:6587-99
Martin, Faye; Baskaran, Padmamalini; Ma, Xiaolei et al. (2010) Structure of cinaciguat (BAY 58-2667) bound to Nostoc H-NOX domain reveals insights into heme-mimetic activation of the soluble guanylyl cyclase. J Biol Chem 285:22651-7
Pattanaik, Priyaranjan; Fromondi, Laura; Ng, Kwok Peng et al. (2009) Expression, purification, and characterization of the intra-cellular domain of the ANP receptor. Biochimie 91:888-93
Ma, Xiaolei; Sayed, Nazish; Baskaran, Padmamalini et al. (2008) PAS-mediated dimerization of soluble guanylyl cyclase revealed by signal transduction histidine kinase domain crystal structure. J Biol Chem 283:1167-78
Sayed, Nazish; Baskaran, Padmamalini; Ma, Xiaolei et al. (2007) Desensitization of soluble guanylyl cyclase, the NO receptor, by S-nitrosylation. Proc Natl Acad Sci U S A 104:12312-7

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