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Critical function of Ikaros in controlling Aiolos gene expression
Author(s) -
Ghadiri Ata,
Duhamel Marianne,
Fleischer Aarne,
Reimann Andreas,
Dessauge Frederic,
Rebollo Angelita
Publication year - 2007
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2007.03.025
Subject(s) - jurkat cells , transcription factor , microbiology and biotechnology , promoter , chromatin immunoprecipitation , biology , gene isoform , transcription (linguistics) , enhancer , gene , gene expression , cell culture , genetics , t cell , linguistics , immune system , philosophy
To characterize the regulation of lymphoid Aiolos transcription factor, we have cloned its promoter. Full promoter and nested deletions were expressed in lymphoid and non‐lymphoid cell lines. The minimal promoter activity could be considered as a 172 bp upstream from the ATG for Jurkat and HEK293 cells and as a 370 bp fragment for U937 cells. Moreover, we have mapped the transcription initiation site. Retardation gels showed binding activity for Ikaros, NFκB and AP4 transcription factors and mutations in their binding sites abolish Aiolos promoter activity. Chromatin immunoprecipitation assay revealed that Ikaros, NFκB and AP4 are bound to Aiolos promoter. The important function of Ikaros and NFκB is underlined by their over expression, which results in the trans‐activation of the promoter and drives Aiolos expression in cell lines and in freshly isolated B and T cells, while over expression of a dominant negative Ikaros isoform is able to block Aiolos expression.