title: Identification of residues in the heme domain of soluble guanylyl cyclase that are important for basal and stimulated catalytic activity.
abstract: Nitric oxide signals through activation of soluble guanylyl cyclase (sGC), a heme-containing heterodimer. NO binds to the heme domain located in the N-terminal part of the β subunit of sGC resulting in increased production of cGMP in the catalytic domain located at the C-terminal part of sGC. Little is known about the mechanism by which the NO signaling is propagated from the receptor domain (heme domain) to the effector domain (catalytic domain), in particular events subsequent to the breakage of the bond between the heme iron and Histidine 105 (H105) of the β subunit. Our modeling of the heme-binding domain as well as previous homologous heme domain structures in different states point to two regions that could be critical for propagation of the NO activation signal. Structure-based mutational analysis of these regions revealed that residues T110 and R116 in the αF helix-β1 strand, and residues I41 and R40 in the αB-αC loop mediate propagation of activation between the heme domain and the catalytic domain. Biochemical analysis of these heme mutants allows refinement of the map of the residues that are critical for heme stability and propagation of the NO/YC-1 activation signal in sGC.
authors.affiliation: Department of Pharmacology and Physiology, New Jersey Medical School, University of Medicine and Dentistry, New Jersey, Newark, New Jersey, United States of America.
authors.forename: Padmamalini
authors.initials: P
authors.lastname: Baskaran
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Heckler
authors.forename: Focco
authors.initials: F
authors.lastname: van den Akker
authors.forename: Annie
authors.initials: A
authors.lastname: Beuve
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D020134:Catalytic Domain; D002522:Chlorocebus aethiops; D004789:Enzyme Activation / Q000235:genetics / Q000502:physiology; D006162:Guanylate Cyclase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006418:Heme / Q000378:metabolism*; D009154:Mutation; D017434:Protein Structure, Tertiary; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000071756:Soluble Guanylyl Cyclase
chemical_list: D018160:Receptors, Cytoplasmic and Nuclear; D006418:Heme; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase
references.citation: EMBO J. 2007 Jan 24;26(2):578-88
references.pmid: 17215864
references.citation: Proc Natl Acad Sci U S A. 2003 Aug 5;100(16):9208-13
references.pmid: 12883009
references.citation: Proc Natl Acad Sci U S A. 2008 Oct 14;105(41):15720-5
references.pmid: 18840690
references.citation: BMC Struct Biol. 2010 Jan 27;10:2
references.pmid: 20105301
references.citation: Proc Natl Acad Sci U S A. 1982 May;79(9):2870-3
references.pmid: 6123998
references.citation: BMC Struct Biol. 2008 Oct 07;8:42
references.pmid: 18842118
references.citation: Handb Exp Pharmacol. 2009;(191):17-31
references.pmid: 19089323
references.citation: FEBS Lett. 2006 Jul 24;580(17):4205-13
references.pmid: 16831427
references.citation: Protein Sci. 2010 Apr;19(4):881-7
references.pmid: 20162612
references.citation: J Biol Chem. 2005 Mar 25;280(12):11513-9
references.pmid: 15649897
references.citation: Biochemistry. 2011 May 24;50(20):4291-7
references.pmid: 21491881
references.citation: Eur J Pharmacol. 2005 Apr 18;513(1-2):67-74
references.pmid: 15878710
references.citation: Science. 2004 Nov 26;306(5701):1550-3
references.pmid: 15472039
references.citation: J Biol Chem. 2004 Jan 23;279(4):3025-32
references.pmid: 14570894
references.citation: J Biol Chem. 1994 Jan 14;269(2):791-3
references.pmid: 7904602
references.citation: J Biol Chem. 2010 Jul 16;285(29):22651-7
references.pmid: 20463019
references.citation: Mol Cell Biochem. 2010 Jan;334(1-2):221-32
references.pmid: 20012469
references.citation: Handb Exp Pharmacol. 2009;(191):33-46
references.pmid: 19089324
references.citation: Proc Natl Acad Sci U S A. 2004 Aug 31;101(35):12854-9
references.pmid: 15326296
references.citation: J Cardiovasc Pharmacol. 1999 Dec;34(6):879-86
references.pmid: 10598133
references.citation: Biochemistry. 2005 Mar 15;44(10):4083-90
references.pmid: 15751985
references.citation: Biochemistry. 2008 Sep 9;47(36):9416-27
references.pmid: 18702531
references.citation: J Biol Chem. 2008 Jan 11;283(2):1167-78
references.pmid: 18006497
references.citation: J Inorg Biochem. 2011 Nov;105(11):1405-12
references.pmid: 21955842