ABSTRACT: Ageing populations pose one of the main public health crises of our time. Reprogramming gene expression by altering the activities of sequence-specific transcription factors (TF) can ameliorate deleterious effects of age. Here we explore how a circuit of TFs coordinates pro-longevity transcriptional outcomes, which reveals a multi-tissue and multi-species role for an entire protein family: the E-twenty-six (ETS) TFs. In Drosophila, reduced insulin/IGF signalling (IIS) extends lifespan by coordinating activation of Aop, an ETS transcriptional repressor, and Foxo, a Forkhead transcriptional activator. Aop and Foxo bind the same genomic loci, and we show that, individually, they effect similar transcriptional programmes in vivo. In combination, Aop can both moderate or synergise with Foxo, dependent on promoter context. Moreover, Foxo and Aop oppose the activities of Pnt, an ETS transcriptional activator, effecting a transcriptomic programme that correlates lifespan outcomes. Directly limiting Pnt extended lifespan, suggesting this is how Aop and Foxo promote longevity. The lifespan-limiting role of Pnt appears to be balanced by a requirement for metabolic regulation in young flies, in which the Aop-Pnt-Foxo circuit determines nutrient storage, and Pnt regulates lipolysis and responses to nutrient stress. Molecular functions are conserved amongst ETS TFs, suggesting others may also affect ageing. We show that Ets21C limits lifespan, functioning in the same genetic network as Foxo and IIS. Other ETS TFs appear to play roles in fly ageing in multiple contexts, since inhibiting the majority of the family in intestine, adipose or neurons extended lifespan. We expand the repertoire of lifespan-limiting ETS TFs in C. elegans, confirming their conserved function in ageing. Altogether this study reveals that roles of ETS TFs in physiology and lifespan are conserved throughout the family, both within and between species.
