Transcriptionally active Stat1 is required for the antiproliferative effects of both interferon alpha and interferon gamma.

• DOI: 10.1073/pnas.93.15.7673
• Publication Date: 2002-07-26T14:43:20Z
• Authors: J F Bromberg; C M Horvath; Z Wen; R D Schreiber; J E Darnell
• Keywords: STAT1; Transcription; IRF8

Type I (alpha, beta) and type II (gamma) interferons (IFNs) can restrict the growth of many cell types. INF-stimulated gene transcription, a key early event in IFN response, acts through Janus kinase-signal transducers activators transcription pathway, which both IFN-alpha IFN-gamma activate factor Stat1. A line lacking Stat1 (U3A) was not growth-arrested by or IFN-gamma, experiments were carried out with U3A cells permanently expressing normal various mutant forms protein. Only complete activity available (Stat1alpha) growth-inhibited IFN-gamma. that supports 20-30% did cause restraint. In contrast, restraint imposed producing Stat1beta, lacks transcriptional activation potential. This parallels earlier results showing truncated function activation. addition to on long-term cultured cells, we also found wild-type primary mouse embryonic fibroblasts inhibited IFNs, but from Stat1-deficient embryos IFNs.