Persistent prion infection disturbs the function of Oct-1, resulting in the down-regulation of murine interferon regulatory factor-3

Homma, Takujiro; Ishibashi, Daisuke; Nakagaki, Takehiro; Fuse, Takayuki; Sano, Kazunori; Satoh, Katsuya; Atarashi, Ryuichiro; Nishida, Noriyuki

Nucleotides -119 to -1 region are responsible for the murine IRF-3 promoter activity. To determine the specific promoter region responsible for murine IRF-3 induction, we generated a series of plasmids that included various sizes of the 59-flanking region of the murine IRF-3 gene fused to the luciferase gene and transfected them into N2a and 3T3 cells. As shown in Fig. 1 , a plasmid containing nt -1000 to -1 relative to the transcription start site (pGL3 -1000/-1) showed approximately 33-fold (in N2a cells) and 6-fold (in 3T3 cells) activity compared with the control (pGL3 Basic), while plasmids containing nt -2000 to -1001 (pGL3 -2000/-1001) and nt -1000 to -524 (pGL3 -1000/-524) completely lost their responsiveness. Plasmids containing nt -523 to -1 (pGL3 -523/-1), nt -340 to -1 (pGL3 -340/-1) and nt -119 to -1 (pGL3 -119/-1) maintained similar levels of their promoter activity with the full-length promoter (pGL3 -1000/-1), suggesting that nt -119 to -1 was responsible for the promoter activity.