Basement membrane ligands initiate distinct signalling networks to direct cell shape

Matrix Biol. 2020 Aug:90:61-78. doi: 10.1016/j.matbio.2020.02.005. Epub 2020 Mar 6.

Abstract

Cells have evolved mechanisms to sense the composition of their adhesive microenvironment. Although much is known about general mechanisms employed by adhesion receptors to relay signals between the extracellular environment and the cytoskeleton, the nuances of ligand-specific signalling remain undefined. Here, we investigated how glomerular podocytes, and four other basement membrane-associated cell types, respond morphologically to different basement membrane ligands. We defined the composition of the respective adhesion complexes using mass spectrometry-based proteomics. On type IV collagen, all epithelial cell types adopted a round morphology, with a single lamellipodium and large adhesion complexes rich in actin-binding proteins. On laminin (511 or 521), all cell types attached to a similar degree but were polygonal in shape with small adhesion complexes enriched in endocytic and microtubule-binding proteins. Consistent with their distinctive morphologies, cells on type IV collagen exhibited high Rac1 activity, while those on laminin had elevated PKCα. Perturbation of PKCα was able to interchange morphology consistent with a key role for this pathway in matrix ligand-specific signalling. Therefore, this study defines the switchable basement membrane adhesome and highlights two key signalling pathways within the systems that determine distinct cell morphologies. Proteomic data are availableviaProteomeXchange with identifier PXD017913.

Keywords: Adhesome; Basement membrane; Cell shape; Laminin; PKC; Rac1; Type IV collagen.

Publication types

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

MeSH terms

  • Animals
  • Basement Membrane / metabolism*
  • Cell Line
  • Cell Shape / drug effects
  • Collagen Type IV / metabolism
  • Ganglia, Spinal / cytology*
  • Ganglia, Spinal / drug effects
  • Ganglia, Spinal / metabolism
  • HEK293 Cells
  • Humans
  • Integrin alpha3 / metabolism
  • Laminin / pharmacology*
  • Ligands
  • Mass Spectrometry
  • Mice
  • Neurons / cytology
  • Neurons / drug effects
  • Neurons / metabolism
  • Neuropeptides / metabolism
  • Protein Kinase C-alpha / metabolism
  • Proteomics / methods*
  • Signal Transduction
  • rac1 GTP-Binding Protein / metabolism

Substances

  • Collagen Type IV
  • Integrin alpha3
  • Itga3 protein, mouse
  • Laminin
  • Ligands
  • Neuropeptides
  • Rac1 protein, mouse
  • Prkca protein, mouse
  • Protein Kinase C-alpha
  • rac1 GTP-Binding Protein