Open AccessNeuronal nitric oxide synthase alternatively spliced forms: Prominent functional localizations in the brain
Author(s) -
Mikael J. L. Eliasson,
Seth Blackshaw,
Michael J. Schell,
Solomon H. Snyder
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.7.3396
Subject(s) - citrulline , exon , nitric oxide synthase , striatum , in situ hybridization , alternative splicing , microbiology and biotechnology , biology , chemistry , messenger rna , nitric oxide , biochemistry , arginine , endocrinology , dopamine , gene , amino acid
Neuronal nitric-oxide synthase (nNOS) is subject to alternative splicing. In mice with targeted deletions of exon 2 (nNOSΔ/Δ ), two alternatively spliced forms, nNOSβ and γ, which lack exon 2, have been described. We have compared localizations of native nNOSα and nNOSβ and γ byin situ hybridization and immunohistochemistry in wild-type and nNOSΔ/Δ mice. To assess nNOS catalytic activity in intact animals we localized citrulline, which is formed stoichiometrically with NO, by immunohistochemistry. nNOSβ is prominent in several brain regions of wild-type animals and shows 2-to 3-fold up-regulation in the cortex and striatum of nNOSΔ/Δ animals. The persistence of much nNOS mRNA and protein, and distinct citrulline immunoreactivity (cit-IR) in the ventral cochlear nuclei and some cit-IR in the striatum and lateral tegmental nuclei, indicate that nNOSβ is a major functional form of the enzyme in these regions. Thus, nNOSβ, and possibly other uncharacterized splice forms, appear to be important physiological sources of NO in discrete brain regions and may account for the relatively modest level of impairment in nNOSΔ/Δ animals.