Editing Nitric oxide synthase (section)

== Species distribution ==

Arginine-derived NO synthesis has been identified in mammals, fish, birds, invertebrates, and bacteria.<ref name="pmid8782597">{{cite book |vauthors=Liu Q, Gross SS | title = Nitric Oxide Part A: Sources and Detection of NO; NO Synthase | chapter = Binding sites of nitric oxide synthases | series = Methods in Enzymology | volume = 268 | pages = 311–24 | year = 1996 | pmid = 8782597 | doi = 10.1016/S0076-6879(96)68033-1 | isbn = 9780121821692 }}</ref> 

Best studied are mammals, where three distinct genes encode NOS [[isozyme]]s: [[neuronal]] (nNOS or NOS-1), [[cytokine]]-inducible (iNOS or NOS-2) and [[endothelial]] (eNOS or NOS-3). iNOS and nNOS are soluble and found predominantly in the [[cytosol]], while eNOS is membrane associated. Evidence has been found for NO signaling in plants, but plant genomes are devoid of homologs to the superfamily which generates NO in other kingdoms.<ref name="pmid7510950">{{cite journal |vauthors=Knowles RG, Moncada S | title = Nitric oxide synthases in mammals | journal = Biochem. J. | volume = 298 | issue = 2| pages = 249–58 |date=March 1994 | doi = 10.1042/bj2980249 | pmid = 7510950 | pmc = 1137932 }}</ref>