The Torpedo electrocyte: a model system for the study of receptor-cytoskeleton interactions.
We have used the electrocyte of Torpedo electric organ as a model system for the study of AchR stabilization in the postsynaptic membrane. Attention was focused on membrane cytoskeleton interactions in particular on a peripheral protein of 43 KD that is believed to participate in AchR immobilization. Using immunocytochemical methods, we have shown that the cortical skeleton in Torpedo electrocyte displays a local differentiation proper for each specialized domain of the plasma membrane. In the postsynaptic membrane, characterized by an accumulation and a geometrical organization of the receptors in the plane of the membrane, the 43 KD protein participates in a submembraneous coating or "postsynaptic densities" that strictly codistribute with the AchR. The 43 KD protein might also account for the anchoring of intermediate-sized filaments. The organization of the postsynaptic domain appears readily different from that of the non-innervated one where the membrane folds are maintained by a cortical meshwork of cytoskeletal proteins such as ankyrin, spectrin and oligomeric actin. In conclusion, the asymmetrical organization of the cortical skeleton in the electrocyte offers a unique opportunity for the study of the specific aspects of membrane-skeleton interactions that take place in the postsynaptic domain.
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure; D003599:Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D004557:Electric Organ / Q000166:cytology* / Q000294:innervation; D029941:Fish Proteins; D008565:Membrane Proteins / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D011950:Receptors, Cholinergic / Q000378:metabolism*; D014101:Torpedo / Q000033:anatomy & histology*
D029941:Fish Proteins; D008565:Membrane Proteins; D011950:Receptors, Cholinergic; C049348:nu 1 protein, Torpedo; D011494:Protein Kinases; D000109:Acetylcholine