GTP-binding proteins are restricted to signal transduction sites.
We have used the Torpedo electric organ to study GTP-binding protein localization since functionally distinct membrane fractions can be isolated from this tissue. Postsynaptic membranes from the innervated face and membranes from the non-innervated face of the electrocyte, as well as presynaptic membranes from the innervating nerve, can be isolated. alpha s was restricted to the innervated face of the postsynaptic cell; alpha i, alpha o, and ras were found only in the presynaptic membrane fraction of the innervating nerve. 21 and 25 kDa GTP-binding proteins were present in all the membrane fractions. These results suggest that specific GTP-binding proteins are differentially restricted to membrane areas specialized in signal transduction.
Mochly-Rosen
D
D
Department of Neurology, University of California, San Francisco General Hospital 94110.
Gordon
A S
AS
D000818:Animals; D001345:Autoradiography; D002462:Cell Membrane / Q000502:physiology; D004557:Electric Organ / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000502:physiology*; D006160:Guanosine Triphosphate / Q000378:metabolism; D008970:Molecular Weight; D010761:Phosphorus Radioisotopes; D015398:Signal Transduction; D013570:Synaptic Membranes / Q000502:physiology*; D014101:Torpedo
D010761:Phosphorus Radioisotopes; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins