A Novel Transactivating Factor That Regulates Interferon-γ-dependent Gene Expression

• Published in: The Journal of biological chemistry Vol. 277; no. 33; p. 30253
• Main Authors: Junbo Hu, Qingjun Meng, Sanjit K. Roy, Abhijit Raha, Jiadi Hu, Jun Zhang, Katsuyuki Hashimoto, Dhananjaya V. Kalvakolanu
• Format: Journal Article
• Language: English
• Published: American Society for Biochemistry and Molecular Biology 16-08-2002
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M202679200

We have previously identified a novel interferon (IFN)-stimulated cis -acting enhancer element, γ-IFN-activated transcriptional element (GATE). GATE differs from the known IFN-stimulated elements
in its primary sequence. Preliminary analysis has indicated that the GATE-dependent transcriptional response requires the
binding of novel transacting factors. A cDNA expression library derived from an IFN-γ-stimulated murine macrophage cell line
was screened with a 32 P-labeled GATE probe to identify the potential GATE-binding factors. A cDNA coding for a novel transcription-activating factor
was identified. Based on its discovery, we named it as GATE-binding factor-1 (GBF-1). GBF-1 homologs are present in mouse,
human, monkey, and Drosophila . It activates transcription from reporter genes carrying GATE. It possesses a strong transactivating activity but has a weak
DNA binding property. GBF-1 is expressed in most tissues with relatively higher steady-state levels in heart, liver, kidney,
and brain. Its expression is induced by IFN-γ treatment. GBF-1 is present in both cytosolic and nuclear compartments. These
studies thus identify a novel transactivating factor in IFN signaling pathways.