PUBLICATION

Autophagosome-lysosome fusion triggers a lysosomal response mediated by TLR9 and controlled by OCRL

Authors
De Leo, M.G., Staiano, L., Vicinanza, M., Luciani, A., Carissimo, A., Mutarelli, M., Di Campli, A., Polishchuk, E., Di Tullio, G., Morra, V., Levtchenko, E., Oltrabella, F., Starborg, T., Santoro, M., di Bernardo, D., Devuyst, O., Lowe, M., Medina, D.L., Ballabio, A., De Matteis, M.A.
ID
ZDB-PUB-170607-12
Date
2016
Source
Nature cell biology   18: 839-50 (Journal)
Registered Authors
Lowe, Martin, Oltrabella, Francesca
Keywords
Autophagosomes, Autophagy, Lysosomes
MeSH Terms
  • Animals
  • Autophagosomes/physiology*
  • Autophagy/genetics
  • Autophagy/physiology*
  • Cell Line
  • Humans
  • Lysosomes/metabolism*
  • Mutation/genetics
  • Oculocerebrorenal Syndrome/genetics
  • Oculocerebrorenal Syndrome/metabolism
  • Phosphatidylinositol 4,5-Diphosphate/metabolism
  • Phosphatidylinositols/genetics*
  • Phosphoric Monoester Hydrolases/genetics*
  • Phosphoric Monoester Hydrolases/metabolism
  • Toll-Like Receptor 9/genetics*
  • Zebrafish
PubMed
27398910 Full text @ Nat. Cell Biol.
Abstract
Phosphoinositides (PtdIns) control fundamental cell processes, and inherited defects of PtdIns kinases or phosphatases cause severe human diseases, including Lowe syndrome due to mutations in OCRL, which encodes a PtdIns(4,5)P2 5-phosphatase. Here we unveil a lysosomal response to the arrival of autophagosomal cargo in which OCRL plays a key part. We identify mitochondrial DNA and TLR9 as the cargo and the receptor that triggers and mediates, respectively, this response. This lysosome-cargo response is required to sustain the autophagic flux and involves a local increase in PtdIns(4,5)P2 that is confined in space and time by OCRL. Depleting or inhibiting OCRL leads to an accumulation of lysosomal PtdIns(4,5)P2, an inhibitor of the calcium channel mucolipin-1 that controls autophagosome-lysosome fusion. Hence, autophagosomes accumulate in OCRL-depleted cells and in the kidneys of Lowe syndrome patients. Importantly, boosting the activity of mucolipin-1 with selective agonists restores the autophagic flux in cells from Lowe syndrome patients.
Genes / Markers
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Human Disease / Model
Sequence Targeting Reagents
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Mapping