Background information: The nuclear gene hSUV3 (human SUV3) encodes an ATP-dependent DNA/RNA helicase. In the yeast Saccharomyces cerevisiae the orthologous Suv3 protein is localized in mitochondria, and is a subunit of the degradosome complex which regulates RNA surveillance and turnover. In contrast, the functions of human SUV3 are not known to date.
Results: In the present study, we show that a fraction of human SUV3 helicase is localized in the nucleus. Using small interfering RNA gene silencing in HeLa cells, we demonstrate that down-regulation of hSUV3 results in cell cycle perturbations and in apoptosis, which is both AIF- and caspase-dependent, and proceeds with the induction of p53.
Conclusions: In addition to its mitochondrial localization, human SUV3 plays an important role in the nucleus and is probably involved in chromatin maintenance.