Identification of an IFN-gamma responsive region in an intron of the invariant chain gene.
The mechanism by which IFN-gamma up-regulates invariant chain mRNA in antigen-presenting cells has been under intensive investigation. This study shows that in murine monocytic cells the transcriptional up-regulation mediated by the invariant chain (Ii) upstream enhancer only accounts for part of the induction of Ii mRNA by IFN-gamma. We have identified an intronic region in the murine Ii gene that contributes to the transcriptional up-regulation by IFN-gamma. The region has S (H), X/X2 and Y boxes similar to those in MHC class II promoters and the Ii upstream enhancer. Mutations at the putative S, X and Y boxes have abolished the ability of the region to mediate Ii up-regulation by IFN-gamma. Consistent with the functions of these boxes, our findings reveal that the up-regulation of Ii transcription by IFN-gamma mediated by the intronic region is dependent on the induction of class II transactivator by IFN-gamma.
Cao
Z A
ZA
Department of Biological Sciences, Stanford University, CA 94305, USA.
Moore
B B
BB
Quezada
D
D
Chang
C H
CH
Jones
P P
PP
D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics*; D001483:Base Sequence; D002478:Cells, Cultured; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007438:Introns; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D020218:Response Elements; D014158:Transcription, Genetic / Q000187:drug effects
D000944:Antigens, Differentiation, B-Lymphocyte; D000949:Histocompatibility Antigens Class II; D012333:RNA, Messenger; C045084:invariant chain; D007371:Interferon-gamma