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WHAMM initiates autolysosome tubulation by promoting actin polymerization on autolysosomes

Anbang Dai1, Li Yu2, Hong-Wei Wang3

  • 1Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking University Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Science, Tsinghua University, 100084, Beijing, China.

Nature Communications
|August 18, 2019
PubMed

Insights

WHAMM protein is essential for autophagic lysosome reformation (ALR). Its absence impairs autolysosome tubulation, leading to enlarged autolysosomes during starvation by disrupting actin scaffold formation.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Autophagy Research

Background:

  • WHAMM (Wiskott-Aldrich syndrome protein family verprolin homologous protein) is an actin nucleation promoting factor (NPF).
  • WHAMM has known associations with membranes and microtubules.
  • The role of WHAMM in cellular processes beyond actin dynamics was unclear.

Purpose of the Study:

  • To investigate the role of WHAMM in autophagic lysosome reformation (ALR).
  • To elucidate the molecular mechanism by which WHAMM regulates ALR.

Main Methods:

  • WHAMM knockout mouse model to study autophagic lysosome reformation.
  • Biochemical assays to analyze WHAMM's interaction with PI(4,5)P2.
  • Microscopy to observe autolysosome morphology and actin dynamics.

Main Results:

  • WHAMM knockout impairs autolysosome tubulation and causes enlarged autolysosomes under starvation.
  • WHAMM is recruited to the autolysosome membrane via PI(4,5)P2 interaction.
  • WHAMM promotes actin scaffold assembly on autolysosomes, facilitating tubulation.

Conclusions:

  • WHAMM is a critical regulator of autophagic lysosome reformation.
  • Actin scaffold assembly mediated by WHAMM is essential for proper autolysosome tubulation.
  • This study reveals a novel function for WHAMM in the autophagy pathway.

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