Neuronal nitric oxide synthase localizes through multiple structural motifs to the sarcolemma in mouse myotubes.
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.
Abdelmoity
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Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9040, USA.
Padre
R C
RC
Burzynski
K E
KE
Stull
J T
JT
Lau
K S
KS
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
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