Mitochondrial metabolites regulate leukaemic and normal stem cells by affecting epigenetic marks. How mitochondrial enzymes localize to the nucleus to control stem cell function is less understood. We discovered that the mitochondrial metabolic enzyme hexokinase 2 (HK2) localizes to the nucleus in leukaemic and normal haematopoietic stem cells. Overexpression of nuclear HK2 increases leukaemic stem cell properties and decreases differentiation, whereas selective nuclear HK2 knockdown promotes differentiation and decreases stem cell function. Nuclear HK2 localization is phosphorylation-dependent, requires active import and export, and regulates differentiation independently of its enzymatic activity. HK2 interacts with nuclear proteins regulating chromatin openness, increasing chromatin accessibilities at leukaemic stem cell-positive signature and DNA-repair sites. Nuclear HK2 overexpression decreases double-strand breaks and confers chemoresistance, which may contribute to the mechanism by which leukaemic stem cells resist DNA-damaging agents. Thus, we describe a non-canonical mechanism by which mitochondrial enzymes influence stem cell function independently of their metabolic function.

线粒体代谢物通过影响表观遗传标记来调节白血病和正常干细胞。人们对线粒体酶如何定位于细胞核以控制干细胞功能知之甚少。我们发现线粒体代谢酶己糖激酶 2 (HK2) 定位于白血病和正常造血干细胞的细胞核。核 HK2 的过表达增加了白血病干细胞的特性并降低了分化，而选择性的核HK2敲低促进分化并降低干细胞功能。核 HK2 定位依赖于磷酸化，需要主动输入和输出，并独立于其酶活性调节分化。HK2 与调节染色质开放性的核蛋白相互作用，增加白血病干细胞阳性特征和 DNA 修复位点的染色质可及性。核 HK2 过表达减少双链断裂并赋予化学抗性，这可能有助于白血病干细胞抵抗 DNA 损伤剂的机制。因此，我们描述了一种非规范机制，线粒体酶通过该机制独立于其代谢功能影响干细胞功能。