XXXX cycle and its possible involvement in the regulation of cytoskeleton-membrane interactions.

@entity1 @entity2366 @entity1423 @entity1426 @entity3900 @entity1718 @entity8859 @entity4357 @entity7609 @entity19260
Receptor-mediated activation of many cells, including blood platelets, leads to changes at the cytoplasmic side of the membrane. In platelets, phospholipases, such as phospholipase C and @entity3900 , have been shown to become activated. From phospholipids they generate the second messengers @entity2366 and @entity19260 (s) and @entity1718 , respectively. At the same time, actin polymerization and reorganization of actin filaments into bundles and networks occurs. Here, the association of lipids, radiolabeled either with saturated ( @entity7609 ) or unsaturated (arachidonic acid) fatty acids, with the cytoskeletons of resting and activated @entity1 blood platelets was studied. The relative binding of lipid components to the cytoskeleton of activated platelets labeled with @entity7609 is six times higher than that of platelets labeled with @entity1426 . Analysis of lipids associated with isolated cytoskeletons of resting and activated platelets (labeled with @entity7609 ) showed a 30-fold increase in the binding of labeled lipids to the cytoskeletal structures during activation. Both @entity2366 and @entity1718 were found to be associated with the cytoskeleton of activated platelets. Gel filtration, chromatofocusing, and immunoprecipitation studies demonstrated tight binding of these lipids to @entity8859 . @entity8859 is one of the proteins that rapidly becomes associated with the cytoskeleton during @entity1423 ; it is also one of the molecules proposed to act as an actin-membrane linker. The results reported indicate a possible participation of @entity8859 , @entity1718 , and the phosphoinositide-derived second messenger @entity2366 in the regulation of cytoskeleton-membrane interactions. Together with the results of others they suggest a possible involvement of the @entity4357 cycle in the assembly of actin filaments and their anchoring to membranes.
