Association of Rho-associated protein kinase 1 with E-cadherin complexes is mediated by p120-catenin

Mol Biol Cell. 2012 Jan;23(1):99-110. doi: 10.1091/mbc.E11-06-0497. Epub 2011 Oct 26.

Abstract

The dynamic functional linkage of cadherins with the underlying actin cytoskeleton is tightly regulated to achieve proper cell-cell adhesion. p120-catenin (p120) regulates both cadherin stability and actin dynamics, but the relationship between these two functions remains unclear. Using a novel proteomic approach called reversible cross-link immunoprecipitation, or ReCLIP, we previously identified a physical interaction between p120 and Rho-associated protein kinase 1 (ROCK1), a major effector of RhoA. In this paper, we show that a discrete fraction of cellular ROCK1 coimmunoprecipitates with p120 and precisely colocalizes to adherens junctions (AJs). Manipulation of AJs using a calcium-switch assay and cadherin-blocking antibodies indicates direct recruitment of ROCK1 to newly forming junctions. Importantly, we find that p120 links ROCK1 to the cadherin complex, as ROCK1 coimmunoprecipitates with wild-type but not p120-uncoupled E-cadherin. Moreover, depletion of ROCK1 using short-hairpin RNA results in dramatic mislocalization of the cadherin complex and junctional actin. These data are consistent with a model in which p120 dynamically regulates Rho-GTPase activity at the cadherin complex through transient interaction with several of its up- and downstream effectors, including ROCK1.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / metabolism
  • Cadherins / metabolism*
  • Catenins / metabolism*
  • Cell Line
  • Delta Catenin
  • Gene Knockdown Techniques
  • Guanine Nucleotide Exchange Factors / metabolism
  • Humans
  • Intercellular Junctions / metabolism
  • Microscopy, Fluorescence
  • Multiprotein Complexes / metabolism
  • Protein Binding
  • Protein Interaction Mapping
  • Protein Transport
  • RNA Interference
  • Repressor Proteins / metabolism
  • rho-Associated Kinases / genetics
  • rho-Associated Kinases / metabolism*

Substances

  • ARHGAP35 protein, human
  • Actins
  • Cadherins
  • Catenins
  • Guanine Nucleotide Exchange Factors
  • Multiprotein Complexes
  • Repressor Proteins
  • ROCK1 protein, human
  • rho-Associated Kinases
  • Delta Catenin
  • CTNND1 protein, human