Syndecan-2 induces filopodia by active cdc42Hs

Exp Cell Res. 1999 May 1;248(2):439-56. doi: 10.1006/excr.1999.4437.


The syndecans, a family of transmembrane heparan sulfate proteoglycans, are ubiquitous molecules whose intracellular function is still unknown. To examine the function of syndecan-2, one of the most abundant heparan sulfate proteoglycan in fibroblasts, we performed transfection studies in COS-1 and Swiss 3T3 cells. Endogenous syndecan-2 colocalized with F-actin in cortical structures. Overexpression of full-length syndecan-2 induced the formation of long filopodia-like structures. These changes correlated with a rearrangement of the actin cytoskeleton, which strongly colocalized with syndecan-2. Overexpression of syndecan-2 lacking the extracellular domain increased the number of microspikes on the cell surface but failed to induce filopodia. Addition of heparin blocked the effect of full-length syndecan-2, suggesting that heparan sulfate chains in the extracellular domain are necessary to induce filopodia. Coexpression of cdc42Hs negative-dominant N17 blocked syndecan-2-induced filopodia and cdc42Hs positive-dominant V12 had a synergic effect. This indicates that active cdc42Hs is necessary for syndecan-2 induction of filopodia. These results provide a link between syndecan-2, actin cytoskeleton, and cdc42Hs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Actins / isolation & purification
  • Animals
  • COS Cells
  • Cell Compartmentation
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cytoskeleton / ultrastructure*
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / metabolism*
  • Heparin / pharmacology
  • Membrane Glycoproteins / biosynthesis*
  • Membrane Glycoproteins / genetics
  • Mice
  • Peptide Fragments / biosynthesis
  • Peptide Fragments / genetics
  • Proteoglycans / biosynthesis*
  • Proteoglycans / genetics
  • Pseudopodia / ultrastructure*
  • Recombinant Proteins / biosynthesis
  • Signal Transduction
  • Syndecan-2
  • cdc42 GTP-Binding Protein


  • Actins
  • Cell Cycle Proteins
  • Membrane Glycoproteins
  • Peptide Fragments
  • Proteoglycans
  • Recombinant Proteins
  • Sdc2 protein, mouse
  • Syndecan-2
  • Heparin
  • GTP-Binding Proteins
  • cdc42 GTP-Binding Protein