NF-X, a transcription factor implicated in MHC class II gene regulation.
The X box has been shown in several assay systems to be a critical element of MHC class II gene promoters. Several X box-binding activities have been discovered in nuclear extracts from a variety of cell lines. The critical question is: which of these are responsible for mediating X box function? This report provides a further characterization of NF-X, a highly specific X box-binding activity we described previously. The cell-type distribution, structural features, and binding site characteristics of NF-X are analyzed in detail, to facilitate comparison with other reported activities. Most importantly, the functional relevance of NF-X is assessed by scanning mutagenesis, and the results indicate that this complex is indeed involved in regulating MHC class II gene expression. With these data in mind, the relationship between NF-X and RF-X, an X box-binding activity reported to be absent in patients with severe combined immunodeficiency, is discussed.
Kouskoff
V
V
Laboratoire de Génétique Moléculaire des Eucaryotes du C.N.R.S. Unité 184 de Biologie Moléculaire et de Génie, Génétique de l'I.N.S.E.R.M., Faculté de Médecine, Strasbourg, France.
Mantovani
R M
RM
Candéias
S M
SM
Dorn
A
A
Staub
A
A
Lisowska-Grospierre
B
B
Griscelli
C
C
Benoist
C O
CO
Mathis
D J
DJ
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D006681:HLA-D Antigens / Q000235:genetics*; D006801:Humans; D008285:Major Histocompatibility Complex; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D009841:Oligonucleotides / Q000737:chemistry; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D006681:HLA-D Antigens; D009687:Nuclear Proteins; D009841:Oligonucleotides; D014157:Transcription Factors