Differential regulation of interferon‐induced mRNAs and c‐myc mRNA by α‐ and γ‐interferons

Publisher Website
Google Scholar
Abstract
The extent and kinetics of induction have been determined for eight mRNAs induced by .alpha.- and .gamma.-interferons in HeLa cells. The mRNAs which code for a 2-5A synthetase, metallothionien II, HLA class I antigen and five unknown proteins were induced 2- > 100-fold by .alpha.-interferons. In the continued presence of .alpha.-interferon some mRNAs were maintained at the induced levels until at least 40 h, whereas others were induced only transiently. When the effects of .alpha.- and .gamma.-interferons were compared, the induced levels and kinetics were very similar for one mRNA (1-8) but were significantly different for the others. One mRNA (6-16) was induced more than 100-fold by .alpha.-interferon but not significantly by .gamma.-interferon. Parallel analysis of the level of c-myc mRNA showed it to decrease twofold in response to .alpha.-interferon, but to increase more than threefold in response to .gamma.-interferon, despite a more profound inhibition of cell growth by the latter. There must, therefore, be differences in how the levels of different mRNAs are sustained by .alpha.-interferons and how .alpha.- and .gamma.-interferons regulate the levels of the same mRNAs.