Plasma membrane tension orchestrates membrane trafficking, cytoskeletal remodeling, and biochemical signaling during phagocytosis

Proc Natl Acad Sci U S A. 2013 Jul 16;110(29):11875-80. doi: 10.1073/pnas.1301766110. Epub 2013 Jul 2.


Phagocytes clear the body of undesirable particles such as infectious agents and debris. To extend pseudopods over the surface of targeted particles during engulfment, cells must change shape through extensive membrane and cytoskeleton remodeling. We observed that pseudopod extension occurred in two phases. In the first phase, pseudopods extended rapidly, with actin polymerization pushing the plasma membrane forward. The second phase occurred once the membrane area from preexisting reservoirs was depleted, leading to increased membrane tension. Increased tension directly altered the small Rho GTPase Rac1, 3'-phosphoinositide, and cytoskeletal organization. Furthermore, it activated exocytosis of vesicles containing GPI-anchored proteins, increasing membrane area and phagocytosis efficiency for large particles. We thus propose that, during phagocytosis, membrane remodeling, cytoskeletal organization, and biochemical signaling are orchestrated by the mechanical signal of membrane tension. These results put a simple mechanical signal at the heart of understanding immunological responses.

Keywords: Rho GTPases; frustrated phagocytosis; immunology; phagocytic cell; traffic.

MeSH terms

  • Actins / metabolism*
  • Animals
  • Bacterial Proteins
  • Biomechanical Phenomena
  • Cell Line, Tumor
  • Cell Membrane / immunology*
  • Cytoskeleton / physiology
  • Fluorescence Resonance Energy Transfer
  • Histidine / analogs & derivatives
  • Histidine / metabolism
  • Luminescent Proteins
  • Mice
  • Microscopy, Confocal / methods
  • Optical Tweezers
  • Phagocytosis / immunology*
  • Pseudopodia / immunology*
  • rac1 GTP-Binding Protein / metabolism


  • Actins
  • Bacterial Proteins
  • Luminescent Proteins
  • yellow fluorescent protein, Bacteria
  • Histidine
  • rac1 GTP-Binding Protein
  • phosphohistidine