DAF-16/FOXO and HLH-30/TFEB comprise a cooperative regulatory axis controlling tubular lysosome induction in C. elegans.

Transcription factors DAF-16/FOXO and HLH-30/TFEB have been linked to aging regulation, but how they synergize to promote longevity is not fully understood. Here, we reveal a functional interaction between these two transcription factors that supports healthier aging in Caenorhabditis elegans. Namely, DAF-16 and HLH-30 cooperate to trigger robust lysosomal tubulation under various contexts, which contributes to systemic health benefits in late age. Remarkably, lysosome tubulation can be artificially induced via overexpression of a small lysosomal gene, dSVIP, in the absence of one transcription factor, but not both. Mechanistically, intestinal overexpression of dSVIP leads to nuclear accumulation of DAF-16 and HLH-30 in gut and non-gut tissues and triggers global gene expression changes, including induction of vps-34 and related lipid-metabolism genes, that promote tubular-lysosome activity. Collectively, our work reveals a cellular process under control of DAF-16 and HLH-30 that elicits pro-health effects in aging.