Related Experiment Video
Updated: May 29, 2026

Application of Genetically Encoded Fluorescent Nitric Oxide (NO•) Probes, the geNOps, for Real-time Imaging of NO• Signals in Single Cells
Published on: March 16, 2017
The beta-isoform of neuronal nitric oxide synthase (nNOS) lacking the PDZ domain is localized at the sarcolemma
Oliver Baum1, Simon Schläppi, Felicitas A Huber-Abel
1Department of Anatomy, University of Bern, Bern, Switzerland. oliver.baum@ana.unibe.ch
Abstract:
In skeletal muscles, the expression of neuronal NO synthase (nNOS) isoforms is uncharacterized at the protein level. We therefore conducted epitope mapping with anti-peptide-antibodies. Antibodies specific for the nNOS N-terminus recognized the 160-kDa alpha-isoform. In contrast, antibodies against the middle portion or the C-terminus of nNOS bound additionally to the truncated 140-kDa beta-isoform which lacks the PDZ-domain present in the alpha-isoform. All nNOS immunohistochemical reactivity was confined to the sarcolemma. Consistently, immunoblotting disclosed both nNOS-isoforms to be co-enriched in the membrane-associated fractions. The beta-isoform was co-immunoprecipitated with alpha-isoform antibodies in muscle extracts indicating an association of both nNOS-isoforms to direct the beta-variant to the sarcolemma.
Related Concept Videos
Nitric Oxide Signaling Pathway
Nuclear Localization Signals and Import
Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors have equal affinities for...
Regulation of Nuclear Protein Sorting
Adrenergic Neurons: Neurotransmission
Synthesis: Catecholamine synthesis requires tyrosine, which is taken...
The Neuromuscular Junction

