Tail domains of myosin-1e regulate phosphatidylinositol signaling and F-actin polymerization at the ventral layer of podosomes

Mol Biol Cell. 2019 Mar 1;30(5):622-635. doi: 10.1091/mbc.E18-06-0398. Epub 2019 Jan 2.

Abstract

During podosome formation, distinct phosphatidylinositol 3,4,5-trisphosphate lipid (PI(3,4,5)P3) production and F-actin polymerization take place at integrin-mediated adhesions. Membrane-associated actin regulation factors, such as myosin-1, serve as key molecules to link phosphatidylinositol signals to podosome assembly. Here, we report that long-tailed myosin-1e (Myo1e) is enriched at the ventral layer of the podosome core in a PI(3,4,5)P3-dependent manner. The combination of TH1 and TH2 (TH12) of Myo1e tail domains contains the essential motif for PI(3,4,5)P3-dependent membrane association and ventral localization at the podosome. TH12 KR2A (K772A and R782A) becomes dissociated from the plasma membrane. While F-actin polymerizations are initialized from the ventral layer of the podosome, TH12 precedes the recruitment of N-WASP and Arp2/3 in the initial phase of podosome formation. Overexpression of TH12, not TH12 KR2A, impedes PI(3,4,5)P3 signaling, restrains F-actin polymerization, and inhibits podosome formation. TH12 also suppresses gelatin degradation and migration speed of invadopodia-forming A375 melanoma cells. Thus, TH12 domain of Myo1e serves as a regulatory component to connect phosphatidylinositol signaling to F-actin polymerization at the podosome.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Animals
  • Cell Line, Tumor
  • Cell Membrane / metabolism
  • Gelatin / metabolism
  • Humans
  • Mice
  • Myosins / chemistry*
  • Myosins / metabolism*
  • Phosphatidylinositol Phosphates / metabolism
  • Phosphatidylinositols / metabolism*
  • Podosomes / metabolism*
  • Polymerization*
  • Protein Binding
  • Protein Domains
  • RAW 264.7 Cells
  • Rats
  • Signal Transduction*

Substances

  • Actins
  • Phosphatidylinositol Phosphates
  • Phosphatidylinositols
  • phosphatidylinositol 3,4,5-triphosphate
  • Gelatin
  • Myosins