HP1a/KDM4A is involved in the autoregulatory loop of the oncogene gene c- Jun

However, the underlying mechanism has not been defined. In this study, we demonstrate that HP1a is involved in the positive autoregulatory loop of the Jra gene, the c-Jun homolog in Drosophila . Jra recruits the HP1a/KDM4A complex to its gene body region upon osmotic stress to reduce H3K36 methylation levels and disrupt H3K36 methylation-dependent histone deacetylation, resulting in high levels of histone acetylation in the Jra gene body region, thus promoting gene transcription.

These results not only expand our knowledge toward the mechanism of c-Jun regulation, but also reveal the mechanism by which HP1a exerts its positive regulatory function in gene expression.