Accumulation of newly synthesized mRNAs in response to human fibroblast (beta) interferon.

Treatment of human fibroblast cells with human fibroblast (beta)interferon for up to 8 hr resulted in the accumulation of at least four mRNAs. The mRNAs were isolated from cellular polysomes and characterized by stimulation of translation in a wheat germ cell-free protein synthesis system. The mRNAs appear as early as 2 hr after exposure to interferon and can be translated in vitro into proteins having molecular weights of 61,000, 62,000, 64,000, and 68,000. The response is not elicited by mouse interferon or insulin and does not occur in the presence of actinomycin D. Chase experiments indicated that the induced mRNAs remain ribosome-associated for at least 3 hr after their synthesis. The appearance of the induced mRNAs correlated directly with the onset of an antiviral state. Velocity sedimentation of the induced mRNAs on sucrose gradients demonstrated that each of the four induced proteins are encoded by different-sized mRNAs.