Macrophage-restricted and interferon gamma-inducible expression of the allograft inflammatory factor-1 gene requires Pu.1.
Expression of allograft inflammatory factor-1 (Aif-1), a 17-kDa protein bearing an EF-hand Ca(2+) binding motif, increases markedly in monocytes and macrophages participating in allo- and autoimmune reactions, including the perivascular inflammation in transplanted hearts, microglial infiltrates in experimental autoimmune neuritis, and the inflamed pancreas of prediabetic BB rats. To investigate the mechanism of this regulation, we isolated the mouse aif-1 gene and determined its genomic organization. The gene has six exons distributed over 1.6 kilobases, an interferon gamma-inducible DNase I-hypersensitive site near -900, and flanking sequences on either side predicted to associate with nuclear matrix. Reporter gene analyses identified sequences between -902 and -789, including consensus Ets and interferon regulatory factor elements, required for macrophage-specific and interferon gamma-inducible transcriptional activity. Pu.1 bound to the Ets site in electromobility shift assay and forced expression of Pu.1 activated the aif-1 promoter in 3T3 fibroblasts, in which it is normally inactive. However, the transcriptional activity of a concatamer of the Ets site alone did not increase with interferon gamma treatment. Cooperation between Pu.1 and proteins binding to the interferon regulatory factor element appears to be necessary for both macrophage-specific and interferon gamma-inducible expression of the aif-1 gene.
Sibinga
Nicholas E S
NE
Department of Medicine, Cardiovascular Division, Albert Einstein College of Medicine, Bronx, New York 10461, USA.nsibinga@aecom.yu.edu
Feinberg
Mark W
MW
Yang
Hongyuan
H
Werner
Frank
F
Jain
Mukesh K
MK
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D000077214:Becaplermin; D002135:Calcium-Binding Proteins / Q000235:genetics*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005091:Exons; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D050835:Interferon Regulatory Factors; D007371:Interferon-gamma / Q000494:pharmacology*; D007375:Interleukin-1 / Q000494:pharmacology; D016753:Interleukin-10 / Q000494:pharmacology; D008262:Macrophage Activation; D008264:Macrophages / Q000502:physiology*; D051379:Mice; D008840:Microfilament Proteins; D008969:Molecular Sequence Data; D015530:Nuclear Matrix / Q000502:physiology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D020574:Proto-Oncogene Proteins c-sis; D011994:Recombinant Proteins / Q000494:pharmacology; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D014184:Transplantation, Homologous / Q000502:physiology; D000099218:Interferon Regulatory Factor-4
D000077214:Becaplermin; D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D050835:Interferon Regulatory Factors; D007371:Interferon-gamma; D007375:Interleukin-1; D016753:Interleukin-10; D008840:Microfilament Proteins; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D011994:Recombinant Proteins; D015534:Trans-Activators; D000099218:Interferon Regulatory Factor-4; C491049:Aif1 protein, mouse