Interferon gamma rapidly induces in human monocytes a DNA-binding factor that recognizes the gamma response region within the promoter of the gene for the high-affinity Fc gamma receptor.

Abstract

Interferon y (IFN-y) transcriptionally activates several early-response genes in monocytes that are important for the ultimate phenotype of the activated macro-

Identification of a Novel Conserved Motif in the STAT Family That Is Required for Tyrosine Phosphorylation

“…RNase Protection Assays-RNase protection assays were performed as described previously (12,13). Briefly, total RNA was isolated with RNAzol B (Tel-Test Inc.).…”

Interferonγ Activation of Raf-1 Is Jak1-dependent and p21ras-independent

“…DNA-binding proteins were assayed as described previously (14). Briefly, 10 g of protein were incubated in binding buffer with the 32 P-labeled oligonucleotide probe consisting of the double-stranded IFN␥ activation sequence (GAS) referred to as the gamma response region (GRR) (5Ј-AGCATGTTTCAAGGATTTGAGAT-GTATTTCCCAGAAAAG-3Ј) of the promoter of the Fcgr1 gene (15).…”

The SH2 Domain-containing Tyrosine Phosphatase PTP1D Is Required for Interferon α/β-induced Gene Expression

“…Binding of IFN␣/␤ to its receptor causes the rapid activation of the Jak tyrosine kinases Jak1 and Tyk2 (6, 7) which results in tyrosine phosphorylation of both Stat1␣ (p91) and Stat2 (p113) (1,17) and the formation of at least two transcription factor complexes. One complex, composed of a heterotrimer of Stat1␣, Stat2, and the DNA binding component p48 (ISGF3␥), binds to interferon-stimulated response elements (ISREs) (18,19), whereas Stat1␣ homodimers bind to ␥ response region (GRR) elements (20).Although much attention has been devoted to the tyrosine kinases involved in Stat activation, the role of tyrosine phosphatases in IFN␣/␤ signal transduction is less understood. Evidence from both in vitro and in vivo studies indicated that tyrosine phosphatases can act as positive as well as negative regulators of the IFN␣/␤-induced Jak/Stat pathway (17,21,22).…”

“…Binding of IFN␣/␤ to its receptor causes the rapid activation of the Jak tyrosine kinases Jak1 and Tyk2 (6, 7) which results in tyrosine phosphorylation of both Stat1␣ (p91) and Stat2 (p113) (1,17) and the formation of at least two transcription factor complexes. One complex, composed of a heterotrimer of Stat1␣, Stat2, and the DNA binding component p48 (ISGF3␥), binds to interferon-stimulated response elements (ISREs) (18,19), whereas Stat1␣ homodimers bind to ␥ response region (GRR) elements (20).…”