Vacuolar pH regulates clathrin-mediated endocytosis through TORC1 signaling during replicative aging

Clathrin-mediated endocytosis (CME) is a critical cellular process that regulates nutrient uptake, membrane composition, and signaling. Although replicative aging affects many cellular functions, its impact on CME remains largely unknown. We show that in budding yeast, older cells have slower assembly of early and coat CME modules, resulting in longer endocytic turnover and reduced Mup1 internalization. This change in CME dynamics is mother cell-specific, and not observed in daughters. Our data also show that perturbing vacuolar pH, a key driver of aging phenotypes, in young cells mimics aging-like CME dynamics, while maintaining an acidic vacuolar pH in aging cells preserves CME dynamics typical of young cells. We demonstrate that the vacuolar pH effect on CME is regulated through TORC1 via the effector kinase Npr1. Finally, we show that rescuing CME in aging cells improves mitochondrial health. These findings reveal that age-associated changes in cellular and vacuolar pH impair CME, and suggest CME as a potential driver of early cellular aging.