Acetylation and modulation of erythroid Kruppel-like factor (EKLF) activity by interaction with histone acetyltransferases

Erythroid Kruppel-like factor (EKLF) is a red cell-specific transcriptional activator that is crucial for consolidating the switch to high levels of adult beta-globin expression during erythroid ontogeny, EKLF is required for integrity of the chromatin structure at the beta-like globin locus, and it interacts with a positive-acting factor in vivo. We find that EKLF is an acetylated transcription factor, and that it interacts in vivo with CBP, p300, and P/CAF, However, its interactions with these histone acetyltransferases are not equivalent, as CBP and p300, but not P/CAF, utilize EKLF as a substrate for in vitro acetylation within its trans-activation region. The functional effects of these interactions are that CBP and p300, but not P/CAF, enhance EKLF's transcriptional activation of the beta-globin promoter in erythroid cells. These results establish EKLF as a tissue specific transcription factor that undergoes post-translational acetylation and suggest a mechanism by which EKLF is able to alter chromatin structure and induce beta-globin expression within the beta-like globin cluster.