Dibutyryladenosine 3':5'-cyclic monophosphate-mediated changes in rat cells involve macromolecular alterations in vinblastine-precipitable proteins.

ts-NT3-KR rat cell cultures show the loss of three components in the molecular-weight region 200,000--250,000 when exposed to dibutyryl cyclic AMP, under conditions of both restriction and expression of the transformed phenotype. Vinblastine is able to precipitate preferentially from control cultures the species that are decreased by exposure to the cyclic nucleotide. Serum-starved cultures exposed to dibutyryl cyclic AMP reveal differences in their vinblastine precipitates, depending on whether the expression of the transformation phenotype is restricted or not.