Programmed cell death 4 modulates lysosomal function by inhibiting TFEB translation

Cell Death Differ. 2021 Apr;28(4):1237-1250. doi: 10.1038/s41418-020-00646-2. Epub 2020 Oct 25.

Abstract

Transcription factor EB (TFEB) is a master regulator of autophagy and lysosomal biogenesis. The post-translational phosphorylation modulations of TFEB by mTOR and ERK signaling can determine its nucleocytoplasmic shuttling and activity in response to nutrient availability. However, regulations of TFEB at translational level are rarely known. Here, we found that programmed cell death 4 (PDCD4), a tumor suppressor, decreased levels of nuclear TFEB to inhibit lysosome biogenesis and function. Mechanistically, PDCD4 reduces global pool of TFEB by suppressing TFEB translation in an eIF4A-dependent manner, rather than influencing mTOR- and ERK2-dependnet TFEB nucleocytoplasmic shuttling. Both of MA3 domains within PDCD4 are required for TFEB translation inhibition. Furthermore, TFEB is required for PDCD4-mediated lysosomal function suppression. In the tumor microenvironment, PDCD4 deficiency promotes the anti-tumor effect of macrophage via enhancing TFEB expression. Our research reveals a novel PDCD4-dependent TFEB translational regulation and supports PDCD4 as a potential therapeutic target for lysosome dysfunction related diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins / metabolism*
  • Autophagy / physiology*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / metabolism*
  • Humans
  • Lysosomes / metabolism*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Phosphorylation
  • Protein Processing, Post-Translational
  • RNA-Binding Proteins / metabolism*
  • Signal Transduction
  • TOR Serine-Threonine Kinases / metabolism

Substances

  • Apoptosis Regulatory Proteins
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • PDCD4 protein, human
  • RNA-Binding Proteins
  • TFEB protein, human
  • TOR Serine-Threonine Kinases