UTX - moonlighting in the cytoplasm?

The X-linked histone demethylase UTX has a pivotal role in cellular and developmental processes including embryogenesis, hematopoiesis and cancer. UTX removes di- and trimethyl groups on histone H3 lysine 27, thereby regulating gene expression. But there is growing evidence that UTX displays biological functions independent of its histone demethylase activity. To elucidate these novel functions, it is of great interest to define subcellular localizations of UTX. Here we show for the first time that native UTX is primarily localized in the cytoplasm whereas ectopic GFP and Flag-tagged UTX display nuclear and cytoplasmic localization. While its epigenetic function is exerted in the nucleus, its cytoplasmic localization points to a novel function.