Association of Rho-associated protein kinase 1 with E-cadherin complexes is mediated by p120-catenin.
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.
Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA.
Andrew L
AL
Smith
Michael R
MR
Dohn
Meredith V
MV
Brown
Albert B
AB
Reynolds
D000199:Actins / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism*; D051177:Catenins / Q000378:metabolism*; D002460:Cell Line; D055785:Gene Knockdown Techniques; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism; D008856:Microscopy, Fluorescence; D046912:Multiprotein Complexes / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping; D021381:Protein Transport; D034622:RNA Interference; D012097:Repressor Proteins / Q000378:metabolism; D054460:rho-Associated Kinases / Q000235:genetics / Q000378:metabolism*; D000095002:Delta Catenin
C074560:ARHGAP35 protein, human; D000199:Actins; D015820:Cadherins; D051177:Catenins; D020662:Guanine Nucleotide Exchange Factors; D046912:Multiprotein Complexes; D012097:Repressor Proteins; C515851:ROCK1 protein, human; D054460:rho-Associated Kinases; D000095002:Delta Catenin; C000722347:CTNND1 protein, human