Nucleotidyl cyclase activity of particulate guanylyl cyclase A: comparison with particulate guanylyl cyclases E and F, soluble guanylyl cyclase and bacterial adenylyl cyclases CyaA and edema factor

PLoS One. 2013 Jul 29;8(7):e70223. doi: 10.1371/journal.pone.0070223. Print 2013.

Abstract

Guanylyl cyclases (GCs) regulate many physiological processes by catalyzing the synthesis of the second messenger cGMP. The GC family consists of seven particulate GCs (pGCs) and a nitric oxide-activated soluble GC (sGC). Rat sGC α1β1 possesses much broader substrate specificity than previously assumed. Moreover, the exotoxins CyaA from Bordetella pertussis and edema factor (EF) from Bacillus anthracis possess nucleotidyl cyclase (NC) activity. pGC-A is a natriuretic peptide-activated homodimer with two catalytic sites that act cooperatively. Here, we studied the NC activity of rat pGC-A in membranes of stably transfected HEK293 cells using a highly sensitive and specific HPLC-MS/MS technique. GTP and ITP were effective, and ATP and XTP were only poor, pGC-A substrates. In contrast to sGC, pGC-A did not use CTP and UTP as substrates. pGC-E and pGC-F expressed in bovine rod outer segment membranes used only GTP as substrate. In intact HEK293 cells, pGC-A generated only cGMP. In contrast to pGCs, EF and CyaA showed very broad substrate-specificity. In conclusion, NCs exhibit different substrate-specificities, arguing against substrate-leakiness of enzymes and pointing to distinct physiological functions of cyclic purine and pyrimidine nucleotides.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylate Cyclase Toxin / metabolism
  • Animals
  • Antigens, Bacterial / metabolism
  • Bacterial Toxins / metabolism
  • Cell Line
  • Cell Membrane / enzymology
  • Cyclic GMP
  • Enzyme Activation
  • Guanylate Cyclase / metabolism
  • HEK293 Cells
  • Humans
  • Kinetics
  • Rats
  • Receptors, Atrial Natriuretic Factor / genetics
  • Receptors, Atrial Natriuretic Factor / metabolism*
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Soluble Guanylyl Cyclase
  • Substrate Specificity

Substances

  • Adenylate Cyclase Toxin
  • Antigens, Bacterial
  • Bacterial Toxins
  • Receptors, Cytoplasmic and Nuclear
  • anthrax toxin
  • Guanylate Cyclase
  • Receptors, Atrial Natriuretic Factor
  • Soluble Guanylyl Cyclase
  • atrial natriuretic factor receptor A
  • Cyclic GMP

Grant support

This work was supported by Deutsche Forschungsgemeinschaft, grant Se 529/5-2 to RS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.