RYR:ATP6V0A1 complexes couple ER-lysosome contact sites to dynamic autophagy control

Ryanodine receptors (RYRs) are ER-resident Ca²⁺-release channels enriched in excitable cells, including neurons. RYR hyperactivity is implicated in early pathogenesis of disorders such as Alzheimer's disease (AD), which is associated with impaired autophagy. We recently uncovered a mechanism linking RYR activity to lysosome availability for autophagy. RYRs localize to ER-lysosome contact sites via direct binding to ATP6V0A1, a V-ATPase subunit that also suppresses RYR-mediated Ca²⁺ release. In human iPSC-derived cortical neurons, spontaneous RYR activity promotes lysosomal secretion, depleting the intracellular lysosomal pool and inhibiting autophagic flux. RYR inhibition promotes ERlysosome contacts, limits lysosomal secretion, and restores lysosome availability for autophagosome fusion and cargo degradation (including APP). Conversely, disrupting the RYR:ATP6V0A1 interaction using a RYR-derived protein fragment serving as a "decoy" for ATP6V0A1 evokes RYR hyperactivity and stimulates lysosomal secretion. In this Punctum, we discuss how this RYR2:ATP6V0A1 "contact-site hub" may be perturbed in disease and highlight open questions on how lysosomes decode RYR-derived Ca²⁺ signals.