The amino acid transporter SLC-36.1 cooperates with PtdIns3P 5-kinase to control phagocytic lysosome reformation

J Cell Biol. 2019 Aug 5;218(8):2619-2637. doi: 10.1083/jcb.201901074. Epub 2019 Jun 24.


Phagocytic removal of apoptotic cells involves formation, maturation, and digestion of cell corpse-containing phagosomes. The retrieval of lysosomal components following phagolysosomal digestion of cell corpses remains poorly understood. Here we reveal that the amino acid transporter SLC-36.1 is essential for lysosome reformation during cell corpse clearance in Caenorhabditis elegans embryos. Loss of slc-36.1 leads to formation of phagolysosomal vacuoles arising from cell corpse-containing phagosomes. In the absence of slc-36.1, phagosome maturation is not affected, but the retrieval of lysosomal components is inhibited. Moreover, loss of PPK-3, the C. elegans homologue of the PtdIns3P 5-kinase PIKfyve, similarly causes accumulation of phagolysosomal vacuoles that are defective in phagocytic lysosome reformation. SLC-36.1 and PPK-3 function in the same genetic pathway, and they directly interact with one another. In addition, loss of slc-36.1 and ppk-3 causes strong defects in autophagic lysosome reformation in adult animals. Our findings thus suggest that the PPK-3-SLC-36.1 axis plays a central role in both phagocytic and autophagic lysosome formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems / metabolism*
  • Animals
  • Apoptosis
  • Autophagy
  • Caenorhabditis elegans / cytology*
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans / ultrastructure
  • Caenorhabditis elegans Proteins / metabolism*
  • Embryo, Nonmammalian / cytology
  • Embryo, Nonmammalian / metabolism
  • Lysosomes / metabolism*
  • Lysosomes / ultrastructure
  • Phagocytosis*
  • Phagosomes / metabolism
  • Phagosomes / ultrastructure
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Solute Carrier Proteins / metabolism*
  • Vacuoles / metabolism
  • Vacuoles / ultrastructure


  • Amino Acid Transport Systems
  • Caenorhabditis elegans Proteins
  • SLC-36.1 protein, C elegans
  • Solute Carrier Proteins
  • PPK-3 protein, C elegans
  • Phosphotransferases (Alcohol Group Acceptor)