Aire's partners in the molecular control of immunological tolerance.
Aire induces the expression of a battery of peripheral-tissue self-antigens (PTAs) in thymic stromal cells, promoting the clonal deletion of differentiating T cells that recognize them. Just how Aire targets and induces PTA transcripts remains largely undefined. Screening via Aire-targeted coimmunoprecipitation followed by mass spectrometry, and validating by multiple RNAi-mediated knockdown approaches, we identified a large set of proteins that associate with Aire. They fall into four major functional classes: nuclear transport, chromatin binding/structure, transcription and pre-mRNA processing. One set of Aire interactions centered on DNA protein kinase and a group of proteins it partners with to resolve DNA double-stranded breaks or promote transcriptional elongation. Another set of interactions was focused on the pre-mRNA splicing and maturation machinery, potentially explaining the markedly more effective processing of PTA transcripts in the presence of Aire. These findings suggest a model to explain Aire's widespread targeting and induction of weakly transcribed chromatin regions.
Abramson
Jakub
J
Department of Pathology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
Giraud
Matthieu
M
Benoist
Christophe
C
Mathis
Diane
D
D000818:Animals; D000951:Antigens, Neoplasm / Q000378:metabolism; D001324:Autoantigens / Q000235:genetics* / Q000276:immunology; D002460:Cell Line; D053903:DNA Breaks, Double-Stranded; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D051747:DNA-Activated Protein Kinase / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007108:Immune Tolerance; D047468:Immunoprecipitation; D013058:Mass Spectrometry; D051379:Mice; D016513:Mice, SCID; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*; D014157:Transcription Factors / Q000378:metabolism*; D000096927:AIRE Protein
D000951:Antigens, Neoplasm; D001324:Autoantigens; D004250:DNA Topoisomerases, Type II; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D000096927:AIRE Protein; C497264:Prkdc protein, mouse