TY - JOUR
T1 - Replacement of 198MQMDII203 of mouse IRF-1 by 197IPVEVV202 of human IRF-1 abrogates induction of IFN-β, iNOS, and COX-2 gene expression by IRF-1
AU - Upreti, Meenakshi
AU - Kumar, Sanjiv
AU - Rath, Pramod C.
N1 - Funding Information:
The kind gift of mouse IRF-1 cDNA (pIRF L plasmid) from Prof. Tadatsugu Taniguchi, Department of Immunology, University of Tokyo; Research Fellowships to M.U. and S.K. from the Council of Scientific and Industrial Research (C.S.I.R.) and the University Grants Commission (U.G.C.), respectively. Financial support through research grants to P.C.R. from the Department of Science and Technology (D.S.T.) and the U.G.C., Govt. of India, is gratefully acknowledged.
PY - 2004/2/13
Y1 - 2004/2/13
N2 - Interferon regulatory factor-1 (IRF-1) is a transcription factor exhibiting functional diversity because of its ability to activate transcription from promoters of several IRF-1-dependent genes. It is a modular protein, where the overall structure is not essential for function of its individual domains. A comparison of the mouse and human IRF-1 amino acid sequences enabled us to identify a stretch of six amino acids (198-203) within the transactivation domain of mouse IRF-1, 198MQMDII203 to be different from that of the human IRF-1, 197IPVEVV 202. This indicated a possible functional significance of the six amino acid stretches in the two IRF-1 molecules. The murine IRF-1 sequence at 198-203 (MQMDII) was replaced by IPVEVV. Recombinant wild type mouse IRF-1 with 198MQMDII203 and its mutant form with 198IPVEVV203, expressed as GST-IRF-1-fusion proteins, showed similar DNA-binding activity. However, ectopic expression of the wild type and mutant IRF-1 in the human embryonic kidney (HEK-293) cells showed the effect of replacement of this region on expression of a few chromosomal genes that are transcriptionally activated by IRF-1 viz. IFN-β, iNOS, and COX-2 genes. In our study, expression of wild type IRF-1 activated these genes as judged by RT-PCR but the mutant IRF-1 did not show this effect. Thus, the MQMDII (198-203 a.a.) region of mouse IRF-1 has a functional context in relation to expression of IRF-1-inducible genes.
AB - Interferon regulatory factor-1 (IRF-1) is a transcription factor exhibiting functional diversity because of its ability to activate transcription from promoters of several IRF-1-dependent genes. It is a modular protein, where the overall structure is not essential for function of its individual domains. A comparison of the mouse and human IRF-1 amino acid sequences enabled us to identify a stretch of six amino acids (198-203) within the transactivation domain of mouse IRF-1, 198MQMDII203 to be different from that of the human IRF-1, 197IPVEVV 202. This indicated a possible functional significance of the six amino acid stretches in the two IRF-1 molecules. The murine IRF-1 sequence at 198-203 (MQMDII) was replaced by IPVEVV. Recombinant wild type mouse IRF-1 with 198MQMDII203 and its mutant form with 198IPVEVV203, expressed as GST-IRF-1-fusion proteins, showed similar DNA-binding activity. However, ectopic expression of the wild type and mutant IRF-1 in the human embryonic kidney (HEK-293) cells showed the effect of replacement of this region on expression of a few chromosomal genes that are transcriptionally activated by IRF-1 viz. IFN-β, iNOS, and COX-2 genes. In our study, expression of wild type IRF-1 activated these genes as judged by RT-PCR but the mutant IRF-1 did not show this effect. Thus, the MQMDII (198-203 a.a.) region of mouse IRF-1 has a functional context in relation to expression of IRF-1-inducible genes.
KW - COX-2
KW - IRF-1
KW - Interferon-β
KW - Transactivation domain
KW - iNOS
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U2 - 10.1016/j.bbrc.2003.12.156
DO - 10.1016/j.bbrc.2003.12.156
M3 - Article
C2 - 14741697
AN - SCOPUS:1542376901
SN - 0006-291X
VL - 314
SP - 737
EP - 744
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -