Spatial proximity of proteins surrounding zyxin under force-bearing conditions

Mol Biol Cell. 2021 Jun 15;32(13):1221-1228. doi: 10.1091/mbc.E19-10-0568. Epub 2021 Apr 28.

Abstract

Sensing physical forces is a critical first step in mechano-transduction of cells. Zyxin, a LIM domain-containing protein, is recruited to force-bearing actin filaments and is thought to repair and strengthen them. Yet, the precise force-induced protein interactions surrounding zyxin remain unclear. Using BioID analysis, we identified proximal proteins surrounding zyxin under normal and force-bearing conditions by label-free mass spectrometry analysis. Under force-bearing conditions, increased biotinylation of α-actinin 1, α-actinin 4, and AFAP1 were detected, and these proteins accumulated along force-bearing actin fibers independently from zyxin, albeit at a lower intensity than zyxin. VASP also accumulated along force-bearing actin fibers in a zyxin-dependent manner, but the biotinylation of VASP remained constant regardless of force, supporting the model of a free zyxin-VASP complex in the cytoplasm being corecruited to tensed actin fibers. In addition, ARHGAP42, a RhoA GAP, was also identified as a proximal protein of zyxin and colocalized with zyxin along contractile actin bundles. The overexpression of ARHGAP42 reduced the rate of small wound closure, a zyxin-dependent process. These results demonstrate that the application of proximal biotinylation can resolve the proximity and composition of protein complexes as a function of force, which had not been possible with traditional biochemical analysis.

Publication types

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

MeSH terms

  • Actin Cytoskeleton / metabolism
  • Actins / metabolism
  • Animals
  • Biomechanical Phenomena / physiology*
  • Cell Adhesion Molecules / metabolism
  • Dogs
  • Focal Adhesions / metabolism
  • Madin Darby Canine Kidney Cells
  • Mechanical Phenomena
  • Microfilament Proteins / metabolism
  • Phosphoproteins / metabolism
  • Stress, Mechanical
  • Zyxin / chemistry
  • Zyxin / metabolism*
  • Zyxin / physiology*

Substances

  • Actins
  • Cell Adhesion Molecules
  • Microfilament Proteins
  • Phosphoproteins
  • Zyxin