Energy status orchestrates YTHDF1 phase separation and tumorigenesis-Accepted Version

Aberrant energy status impacts the initiation and progression of tumorigenesis, although the underlying mechanisms remain poorly understood. Adenosine monophosphate (AMP)-activated protein kinase (AMPK), a key sensor of cellular energy stress, is activated to facilitate metabolic adaptation and regulate tumorigenesis. Here, we reveal that energy deprivation-induced activation of AMPK phosphorylates YTHDF1 at Ser198, counteracting its O-GlcNAcylation. This phosphorylation alters the functional properties of YTHDF1 by suppressing its phase separation and its interaction with the translation initiation factor eIF3b, ultimately reducing protein translation. Notably, enhancing YTHDF1 phosphorylation to antagonize its O-GlcNAcylation through AMPK agonists or ketogenic diet effectively inhibits tumor cell growth both in vitro and in vivo. These findings elucidate a regulatory mechanism that links cellular energy status to YTHDF1 post-translational modifications and highlight the therapeutic potential of targeting YTHDF1-mediated pathways via metabolic interventions for cancer treatment.