Induction and regulation of the 26-kDa protein in the absence of synthesis of beta-interferon mRNA in human cells.
The expression of the gene coding for the 26-kDa protein coinduced with human beta-interferon (HuIFN-beta) in human fibroblasts has been measured by cytoplasmic dot hybridization in WISH cells. The production of the 26-kDa-protein mRNA is not induced by poly(I).poly(C) but maximally induced by cycloheximide alone. In contrast, HuIFN-beta is induced by poly(I).poly(C) and not by cycloheximide. WISH cells showed in addition a low constitutive level of 26-kDa-protein mRNA prior to induction. These results were confirmed by sizing the RNAs by Northern blot analysis. Pretreatment with partially purified or pure IFN-beta has only a slight effect on 26-kDa protein mRNA production. We have also determined the kinetics of induction and the amount of inducer required for an optimal induction of the 26-kDa-protein mRNA in WISH cells. This mRNA was thus maximally induced in WISH cells in the absence of detectable IFN-beta; it represents about 0.05% of poly(A)-rich mRNA in cycloheximide-induced WISH cells. We had already found that the 26-kDa-protein does not share the general characteristics of interferons. These results suggest that HuIFN-beta and the 26-kDa-protein genes are differently regulated.
D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007370:Interferon Type I / Q000235:genetics*; D007700:Kinetics; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D011070:Poly I-C / Q000494:pharmacology; D014176:Protein Biosynthesis / Q000187:drug effects; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis*
D007370:Interferon Type I; D011506:Proteins; D012333:RNA, Messenger; D003513:Cycloheximide; D011070:Poly I-C