ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: The G proteins Gs and Gi1 appear to be capable of binding to tubulin specifically, and it has been suggested that such binding results in G protein activation via direct transfer of GTP. This study was undertaken to demonstrate that consequences of G protein activation by tubulin, i.e., stimulation or inhibition of adenylyl cyclase, were dependent on the G proteins expressed as well as unique aspects of the membrane or cytoskeleton in a given cell type. Membranes from rat C6 glioma cells, which express Gsα but not Giα1, responded to the addition of tubulin with a stable activation of adenylyl cyclase. Conversely, membranes from rat cerebral cortex, which contain both Gs and Gi1, responded to exogenous tubulin with a stable inhibition of adenylyl cyclase. Unlike C6 membranes, cerebral cortex membranes are richly endowed with tubulin, and antitubulin antibodies immunoprecipitated complexes of tubulin and Gi1 or Gs from detergent extracts of these membranes. Nearly 90% of the Gsα from Triton X-114 extracts coimmunoprecipitated with tubulin, suggesting that these proteins exist as a complex in the synaptic membrane. Such complexes may provide the framework for a G protein-cytoskeleton link that participates in the modulation of cellular signal transduction.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1471-4159.1996.66041489.x
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