title: Mapping Soluble Guanylyl Cyclase and Protein Disulfide Isomerase Regions of Interaction.
abstract: Soluble guanylyl cyclase (sGC) is a heterodimeric nitric oxide (NO) receptor that produces cyclic GMP. This signaling mechanism is a key component in the cardiovascular system. NO binds to heme in the β subunit and stimulates the catalytic conversion of GTP to cGMP several hundred fold. Several endogenous factors have been identified that modulate sGC function in vitro and in vivo. In previous work, we determined that protein disulfide isomerase (PDI) interacts with sGC in a redox-dependent manner in vitro and that PDI inhibited NO-stimulated activity in cells. To our knowledge, this was the first report of a physical interaction between sGC and a thiol-redox protein. To characterize this interaction between sGC and PDI, we first identified peptide linkages between sGC and PDI, using a lysine cross-linking reagent and recently developed mass spectrometry analysis. Together with Flag-immunoprecipitation using sGC domain deletions, wild-type (WT) and mutated PDI, regions of sGC involved in this interaction were identified. The observed data were further explored with computational modeling to gain insight into the interaction mechanism between sGC and oxidized PDI. Our results indicate that PDI interacts preferentially with the catalytic domain of sGC, thus providing a mechanism for PDI inhibition of sGC. A model in which PDI interacts with either the α or the β catalytic domain is proposed.
authors.affiliation: Department of Pharmacology and Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, United States of America.
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Heckler
authors.affiliation: High Performance and Research Computing, OIRT, Rutgers University, New Brunswick, NJ, United States of America.|Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America.
authors.forename: Vladyslav
authors.initials: V
authors.lastname: Kholodovych
authors.affiliation: Proteomics Core, New Jersey Medical School, Rutgers University, Newark, NJ, United States of America.
authors.forename: Mohit
authors.initials: M
authors.lastname: Jain
authors.affiliation: Proteomics Core, New Jersey Medical School, Rutgers University, Newark, NJ, United States of America.
authors.forename: Tong
authors.initials: T
authors.lastname: Liu
authors.affiliation: Proteomics Core, New Jersey Medical School, Rutgers University, Newark, NJ, United States of America.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Pharmacology and Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, United States of America.
authors.forename: Annie
authors.initials: A
authors.lastname: Beuve
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D020134:Catalytic Domain; D002522:Chlorocebus aethiops; D006162:Guanylate Cyclase / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D019704:Protein Disulfide-Isomerases / Q000737:chemistry* / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000378:metabolism; D000071756:Soluble Guanylyl Cyclase
chemical_list: D018160:Receptors, Cytoplasmic and Nuclear; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D019704:Protein Disulfide-Isomerases