Gene

Biogenesis

Cell biology

TFEB

Biology

Lysosome

Apoptosis

Extracellular

Autophagy

Regeneration (biology)

Biochemistry

Endocytosis

Intracellular

Homeostasis

Planarian

Enzyme

Organelle biogenesis

Chemistry

Cell

Endocytic cycle

Nature Cell Biology

Lysosomes serve as cellular degradation and signalling centres that coordinate metabolism in response to intracellular cues and extracellular signals. Lysosomal capacity is adapted to cellular needs by transcription factors, such as TFEB and TFE3, which activate the expression of lysosomal and autophagy genes. Nuclear translocation and activation of TFEB are induced by a variety of conditions such as starvation, lysosome stress and lysosomal storage disorders. How these various cues are integrated remains incompletely understood. Here, we describe a pathway initiated at the plasma membrane that controls lysosome biogenesis via the endocytic regulation of intracellular ion homeostasis. This pathway is based on the exo-endocytosis of NHE7, a Na+/H+ exchanger mutated in X-linked intellectual disability, and serves to control intracellular ion homeostasis and thereby Ca2+/calcineurin-mediated activation of TFEB and downstream lysosome biogenesis in response to osmotic stress to promote the turnover of toxic proteins and cell survival. López-Hernández et al. show that exo-endocytosis of a Na+/H+ exchanger controls lysosome biogenesis through Ca2+/calcineurin-mediated activation of TFEB in response to osmotic stress.

Endocytic regulation of cellular ion homeostasis controls lysosome biogenesis