LNK (SH2B3) is a key regulator of integrin signaling in endothelial cells and targets α-parvin to control cell adhesion and migration

FASEB J. 2012 Jun;26(6):2592-606. doi: 10.1096/fj.11-193383. Epub 2012 Mar 21.

Abstract

Focal adhesion (FA) formation and disassembly play an essential role in adherence and migration of endothelial cells. These processes are highly regulated and involve various signaling molecules that are not yet completely identified. Lnk [Src homology 2-B3 (SH2B3)] belongs to a family of SH2-containing proteins with important adaptor functions. In this study, we showed that Lnk distribution follows that of vinculin, localizing Lnk in FAs. Inhibition of Lnk by RNA interference resulted in decreased spreading, whereas sustained expression dramatically increases the number of focal and cell-matrix adhesions. We demonstrated that Lnk expression impairs FA turnover and cell migration and regulates β1-integrin-mediated signaling via Akt and GSK3β phosphorylation. Moreover, the α-parvin protein was identified as one of the molecular targets of Lnk responsible for impaired FA dynamics and cell migration. Finally, we established the ILK protein as a new molecular partner for Lnk and proposed a model in which Lnk regulates α-parvin expression through its interaction with ILK. Collectively, our results underline the adaptor Lnk as a novel and effective key regulator of integrin-mediated signaling controlling endothelial cell adhesion and migration.

Publication types

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

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Cell Adhesion / drug effects*
  • Cell Movement / drug effects*
  • Cell-Matrix Junctions / metabolism
  • Focal Adhesions / drug effects
  • Focal Adhesions / physiology*
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Integrin beta1 / physiology
  • Intracellular Signaling Peptides and Proteins
  • Microfilament Proteins / metabolism*
  • Protein Serine-Threonine Kinases / metabolism*
  • Proteins / physiology*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / physiology*

Substances

  • Adaptor Proteins, Signal Transducing
  • Integrin beta1
  • Intracellular Signaling Peptides and Proteins
  • Microfilament Proteins
  • PARVA protein, human
  • Proteins
  • SH2B3 protein, human
  • integrin-linked kinase
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt