Post-transcriptional effect of ultraviolet light on gene expression in human cells: Stabilization of cytokine-induced and poly(I) multiplied by poly(C)-induced messenger RNA

This analysis has focused on six genes whose transcription is conditional on the supply of exogenous inducers, interferon- alpha , interleukin-1 alpha or the double-stranded RNA, poly(I) multiplied by poly(C). Human cells induced to express these genes were found to retain a significantly higher concentration of corresponding transcripts when irradiated with ultraviolet light at the end of the inducing treatment. This stimulation was due to dose-dependent ultraviolet-light stabilization of preformed mRNA, as shown by run-on and pulse/chase experiments. This work uncovers a new facet of the cellular response to genotoxic stresses, i.e. extension of the life-span of transcription products.