Effect of the AIR-1 locus on the activation of an enhancerless HLA-DQA1 promoter.
Studies on the regulation of a major histocompatibility complex (MHC) class II gene, HLA-DQA1, in Ia-positive cells (Raji, a human B-lymphoma cell line) and in isogenic Ia-negative cells (RJ2.2.5, a mutant of Raji altered at the AIR-1 locus) are reported. As previously found, AIR-1 is required in its entirety for the activity of an enhancer factor, the absence of which abolishes transcription of MHC class II genes. In this paper, we show that HLA-DQA1 gene expression can be directed by an enhancerless promoter. The fact that this promoter is inactive in the RJ2.2.5 mutant suggests that the trans-acting element determined by the AIR-1 locus is not only an enhancer factor as previously described, but also acts at the MHC class II promoter level.
Ombra
M N
MN
International Institute of Genetics and Biophysics, Napoli, Italy.
Del Pozzo
G
G
Perfetto
C
C
Maffei
A
A
Guardiola
J
J
D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D002874:Chromosome Mapping; D005786:Gene Expression Regulation / Q000276:immunology; D006683:HLA-DQ Antigens / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D014162:Transfection
D006683:HLA-DQ Antigens; D011993:Recombinant Fusion Proteins; D015500:Chloramphenicol O-Acetyltransferase