Tumor protein D52 (TPD52) affects cancer cell metabolism by negatively regulating AMPK.

The AMP-activated protein kinase (AMPK) is a central regulator of energy homeostasis, with deregulation leading to cancer and other diseases. When intracellular ATP levels decrease during energy stress, AMPK is phosphorylated and activated through AMP binding. However, how this pathway is dysregulated in cancer remains unclear. Here, we find that tumor protein D52 (TPD52), initially identified to be overexpressed in many human cancers, forms a stable complex with AMPK in cancer cells. TPD52 directly interacts with AMPK and inhibits AMPK kinase activity in vitro and in vivo. We generated TPD52 transgenic mice, and found that overexpression of TPD52 leads to AMPK inhibition and multiple metabolic defects in mice. Together, our results shed new light on AMPK regulation and on our understanding of the etiology of cancers with TPD52 overexpression.