title: Neuronal nitric oxide synthase localizes through multiple structural motifs to the sarcolemma in mouse myotubes.
abstract: In skeletal muscle, neuronal nitric oxide synthase is localized at the sarcolemma in association with the dystrophin glycoprotein complex (DGC). The nNOS N-terminal 231 amino acids comprise a PDZ domain (residues 1-100) and a beta-hairpin finger loop (residues 101-130) which binds alpha-syntrophin located in the DGC. Endogenous nNOS and GFP-tagged nNOS localize to the sarcolemma in mouse C2C12 myotubes. Expression of GFP-tagged nNOS domains in C2C12 myotubes reveals that the PDZ domain and the beta-hairpin finger loop of nNOS are independently capable of localizing to the sarcolemma of C2C12 myotubes. Binding studies indicate that alpha-syntrophin binds only to the beta-hairpin finger loop and not the PDZ domain of nNOS. nNOS may bind to proteins in addition to alpha-syntrophin at muscle sarcolemma.
authors.affiliation: Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9040, USA.
authors.forename: A
authors.initials: A
authors.lastname: Abdelmoity
authors.forename: R C
authors.initials: RC
authors.lastname: Padre
authors.forename: K E
authors.initials: KE
authors.lastname: Burzynski
authors.forename: J T
authors.initials: JT
authors.lastname: Stull
authors.forename: K S
authors.initials: KS
authors.lastname: Lau
mesh_terms: D000818:Animals; D019556:COS Cells; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000648:ultrastructure; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000378:metabolism; D012508:Sarcolemma / Q000201:enzymology*; D014162:Transfection
chemical_list: D002135:Calcium-Binding Proteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; D009124:Muscle Proteins; D011993:Recombinant Fusion Proteins; C091825:syntrophin alpha1; D049452:Green Fluorescent Proteins; C496320:NOS1 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496321:Nos1 protein, mouse