title: Soluble guanylyl cyclase requires heat shock protein 90 for heme insertion during maturation of the NO-active enzyme.
abstract: Heme insertion is key during maturation of soluble guanylyl cyclase (sGC) because it enables sGC to recognize NO and transduce its multiple biological effects. Although sGC is often associated with the 90-kDa heat shock protein (hsp90) in cells, the implications are unclear. The present study reveals that hsp90 is required to drive heme insertion into sGC and complete its maturation. We used a mammalian cell culture approach and followed heme insertion into transiently and endogenously expressed heme-free sGC. We used pharmacological hsp90 inhibitors, an ATP-ase inactive hsp90 mutant, and heme-dependent or heme-independent sGC activators as tools to decipher the role of hsp90. Our findings suggest that hsp90 complexes with apo-sGC, drives heme insertion through its inherent ATPase activity, and then dissociates from the mature, heme-replete sGC. Together, this improves our understanding of sGC maturation and reveals a unique means to control sGC activity in cells, and it has important implications for hsp90 inhibitor-based cancer therapy.
authors: Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
authors: Arnab
authors: A
authors: Ghosh
authors: Dennis J
authors: DJ
authors: Stuehr
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D004797:Enzyme-Linked Immunosorbent Assay; D006162:Guanylate Cyclase / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D006418:Heme / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D000071756:Soluble Guanylyl Cyclase
chemical_list: D018841:HSP90 Heat-Shock Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D009569:Nitric Oxide; D006418:Heme; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase