An RPTPα/Src family kinase/Rap1 signaling module recruits myosin IIB to support contractile tension at apical E-cadherin junctions

Mol Biol Cell. 2015 Apr 1;26(7):1249-62. doi: 10.1091/mbc.E14-07-1223. Epub 2015 Jan 28.

Abstract

Cell-cell adhesion couples the contractile cortices of epithelial cells together, generating tension to support a range of morphogenetic processes. E-cadherin adhesion plays an active role in generating junctional tension by promoting actin assembly and cortical signaling pathways that regulate myosin II. Multiple myosin II paralogues accumulate at mammalian epithelial cell-cell junctions. Earlier, we found that myosin IIA responds to Rho-ROCK signaling to support junctional tension in MCF-7 cells. Although myosin IIB is also found at the zonula adherens (ZA) in these cells, its role in junctional contractility and its mode of regulation are less well understood. We now demonstrate that myosin IIB contributes to tension at the epithelial ZA. Further, we identify a receptor type-protein tyrosine phosphatase alpha-Src family kinase-Rap1 pathway as responsible for recruiting myosin IIB to the ZA and supporting contractile tension. Overall these findings reinforce the concept that orthogonal E-cadherin-based signaling pathways recruit distinct myosin II paralogues to generate the contractile apparatus at apical epithelial junctions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adherens Junctions / metabolism
  • Adherens Junctions / physiology*
  • Cadherins / metabolism*
  • Epithelial Cells / metabolism
  • Epithelial Cells / physiology*
  • Female
  • Humans
  • MCF-7 Cells
  • Nonmuscle Myosin Type IIB / metabolism*
  • Receptor-Like Protein Tyrosine Phosphatases, Class 4 / metabolism*
  • Signal Transduction
  • rap1 GTP-Binding Proteins / metabolism*
  • src-Family Kinases / metabolism*

Substances

  • Cadherins
  • src-Family Kinases
  • PTPRA protein, human
  • Receptor-Like Protein Tyrosine Phosphatases, Class 4
  • Nonmuscle Myosin Type IIB
  • rap1 GTP-Binding Proteins