A Novel RGD-independent Cell Adhesion Pathway Mediated by Fibronectin-bound Tissue Transglutaminase Rescues Cells from Anoikis

Elisabetta A.M. Verderio, Dilek Telci, Afam Okoye, Gerry Melino, Martin Griffin

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104 Scopus citations


Specific association of tissue transglutaminase (tTG) with matrix fibronectin (FN) results in the formation of an extracellular complex (tTG-FN) with distinct adhesive and pro-survival characteristics. tTG-FN supports RGD-independent cell adhesion of different cell types and the formation of distinctive RhoA-dependent focal adhesions following inhibition of integrin function by competitive RGD peptides and function blocking anti-integrin antibodies α5β1. Association of tTG with its binding site on the 70-kDa amino-terminal FN fragment does not support this cell adhesion process, which seems to involve the entire FN molecule. RGD-independent cell adhesion to tTG-FN does not require transamidating activity, is mediated by the binding of tTG to cell-surface heparan sulfate chains, is dependent on the function of protein kinase Cα, and leads to activation of the cell survival focal adhesion kinase. The tTG-FN complex can maintain cell viability of tTG-null mouse dermal fibroblasts when apoptosis is induced by inhibition of RGD-dependent adhesion (anoikis), suggesting an extracellular survival role for tTG. We propose a novel RGD-independent cell adhesion mechanism that promotes cell survival when the anti-apoptotic role mediated by RGD-dependent integrin function is reduced as in tissue injury, which is consistent with the externalization and binding of tTG to fibronectin following cell damage/stress.

Original languageEnglish (US)
Pages (from-to)42604-42614
Number of pages11
JournalJournal of Biological Chemistry
Issue number43
StatePublished - Oct 24 2003


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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