<p>Lysosomal and endoplasmic reticulum (ER) Ca<sup>2+</sup> release mutually influence each other’s functions. Recent work revealed that ER-located ryanodine receptor(s) (RyR(s)) Ca<sup>2+</sup> release channels suppress autophagosome turnover by the lysosomes. In familial Alzheimer’s disease, inhibiting RyR hyperactivity restored autophagic flux by normalizing lysosomal vacuolar H<sup>+</sup>-ATPase (vATPase) levels. However, the mechanisms by which RyRs control lysosomal function and how this involves the vATPase remain unknown. Here, we show that RyRs interact with the ATP6v0a1 subunit of the vATPase, contributing to ER-lysosomal contact site formation. This interaction suppresses RyR-mediated Ca²⁺ release, leading to reduced lysosomal exocytosis. Pharmacological inhibition of RyR activity mimics these effects on lysosomal exocytosis. Retaining lysosomes inside cells via RyR inhibition increases ER-lysosomal contact site formation, rendering lysosomes more available for autophagic flux. In summary, these findings establish RyR/ATP6v0a1 complexes as ER-lysosomal tethers that dynamically&#xa0;and&#xa0;Ca<sup>2+</sup> dependently regulate the intracellular availability of lysosomes to participate in autophagic flux.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Inactive ryanodine receptors sustain lysosomal availability for autophagy by promoting ER-lysosomal contact site formation

  • Tim Vervliet,
  • Jens Loncke,
  • Marko Sever,
  • Karan Ahuja,
  • Chris Van den Haute,
  • Tomas Luyten,
  • Grace E. Stutzmann,
  • Catherine Verfaillie,
  • Tihomir Tomašič,
  • Geert Bultynck

摘要

Lysosomal and endoplasmic reticulum (ER) Ca2+ release mutually influence each other’s functions. Recent work revealed that ER-located ryanodine receptor(s) (RyR(s)) Ca2+ release channels suppress autophagosome turnover by the lysosomes. In familial Alzheimer’s disease, inhibiting RyR hyperactivity restored autophagic flux by normalizing lysosomal vacuolar H+-ATPase (vATPase) levels. However, the mechanisms by which RyRs control lysosomal function and how this involves the vATPase remain unknown. Here, we show that RyRs interact with the ATP6v0a1 subunit of the vATPase, contributing to ER-lysosomal contact site formation. This interaction suppresses RyR-mediated Ca²⁺ release, leading to reduced lysosomal exocytosis. Pharmacological inhibition of RyR activity mimics these effects on lysosomal exocytosis. Retaining lysosomes inside cells via RyR inhibition increases ER-lysosomal contact site formation, rendering lysosomes more available for autophagic flux. In summary, these findings establish RyR/ATP6v0a1 complexes as ER-lysosomal tethers that dynamically and Ca2+ dependently regulate the intracellular availability of lysosomes to participate in autophagic flux.