Identification of a dynein molecular motor component in Torpedo electroplax; binding and phosphorylation of Tctex-1 by Fyn.
The microtubule protein Tctex-1 was cloned from Torpedo electroplax, a biochemical model of the neuromuscular junction, using the unique domain of Fyn in the yeast two hybrid system. Binding of Tctex-1 and Fyn also occurred in vitro. Torpedo Tctex-1 was contained within the molecular motor protein dynein. A Src class kinase was also complexed with dynein. Tctex-1 was enriched in electric organ vs. skeletal muscle, was present in the postsynaptic membrane, and coprecipitated with the acetylcholine receptor. The sequence of Tctex-1 contained a tyrosine phosphorylation motif and Tctex-1 could be phosphorylated by Fyn in vitro and in vivo. These data demonstrated that Tctex-1-containing dynein is a cytoskeletal element at the acetylcholine receptor-enriched postsynaptic membrane and suggested that Tctex-1 may be a substrate for Fyn.
Department of Neurology, Georgetown Institute for Cognitive and Computational Sciences, Georgetown University Medical Center, Washington, DC 20007, USA.
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Mou
J R
JR
Kraas
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Fung
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SL
Swope
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004398:Dyneins / Q000235:genetics / Q000378:metabolism*; D008868:Microtubule Proteins / Q000235:genetics* / Q000378:metabolism; D008869:Microtubule-Associated Proteins; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D010766:Phosphorylation; D014101:Torpedo / Q000235:genetics* / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism*; D056427:t-Complex Genome Region
D008868:Microtubule Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D019061:src-Family Kinases; D004398:Dyneins