Abstract
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.
Original language | English |
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Pages (from-to) | 3197-204 |
Number of pages | 8 |
Journal | Journal of immunology (Baltimore, Md. : 1950) |
Volume | 146 |
Issue number | 9 |
Publication status | Published - 1 May 1991 |
Keywords
- Animals
- Base Sequence
- Cell Line
- DNA-Binding Proteins
- Gene Expression Regulation
- HLA-D Antigens
- Humans
- Major Histocompatibility Complex
- Mice
- Molecular Sequence Data
- Nuclear Proteins
- Oligonucleotides
- Promoter Regions, Genetic
- Regulatory Sequences, Nucleic Acid
- Transcription Factors
- Transcription, Genetic
- Journal Article
- Research Support, Non-U.S. Gov't