Protrudin-mediated ER-endosome contact sites promote MT1-MMP exocytosis and cell invasion

J Cell Biol. 2020 Aug 3;219(8):e202003063. doi: 10.1083/jcb.202003063.


Cancer cells break tissue barriers by use of small actin-rich membrane protrusions called invadopodia. Complete invadopodia maturation depends on protrusion outgrowth and the targeted delivery of the matrix metalloproteinase MT1-MMP via endosomal transport by mechanisms that are not known. Here, we show that the ER protein Protrudin orchestrates invadopodia maturation and function. Protrudin formed contact sites with MT1-MMP-positive endosomes that contained the RAB7-binding Kinesin-1 adaptor FYCO1, and depletion of RAB7, FYCO1, or Protrudin inhibited MT1-MMP-dependent extracellular matrix degradation and cancer cell invasion by preventing anterograde translocation and exocytosis of MT1-MMP. Moreover, when endosome translocation or exocytosis was inhibited by depletion of Protrudin or Synaptotagmin VII, respectively, invadopodia were unable to expand and elongate. Conversely, when Protrudin was overexpressed, noncancerous cells developed prominent invadopodia-like protrusions and showed increased matrix degradation and invasion. Thus, Protrudin-mediated ER-endosome contact sites promote cell invasion by facilitating translocation of MT1-MMP-laden endosomes to the plasma membrane, enabling both invadopodia outgrowth and MT1-MMP exocytosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Video-Audio Media

MeSH terms

  • Breast Neoplasms / enzymology*
  • Breast Neoplasms / genetics
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Cell Movement*
  • Endoplasmic Reticulum / enzymology*
  • Endoplasmic Reticulum / genetics
  • Endoplasmic Reticulum / pathology
  • Endosomes / enzymology*
  • Endosomes / genetics
  • Endosomes / pathology
  • Exocytosis*
  • Extracellular Matrix / enzymology
  • Extracellular Matrix / pathology
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Matrix Metalloproteinase 14 / genetics
  • Matrix Metalloproteinase 14 / metabolism*
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism
  • Neoplasm Invasiveness
  • Podosomes / enzymology
  • Podosomes / genetics
  • Podosomes / pathology
  • Protein Transport
  • Signal Transduction
  • Synaptotagmins / genetics
  • Synaptotagmins / metabolism
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*
  • rab GTP-Binding Proteins / genetics
  • rab GTP-Binding Proteins / metabolism


  • FYCO1 protein, human
  • Microtubule-Associated Proteins
  • SYT7 protein, human
  • Vesicular Transport Proteins
  • ZFYVE27 protein, human
  • Synaptotagmins
  • rab7 protein
  • MMP14 protein, human
  • Matrix Metalloproteinase 14
  • rab GTP-Binding Proteins