Syndecans-2 and -4; close cousins, but not identical twins

Mol Cells. 2004 Apr 30;17(2):181-7.


The vertebrate syndecans, which make up a four-member family of small type I transmembrane heparan sulfate proteoglycans, constitute evolutionarily conserved family proteins. In particular, sequences in the transmembrane and cytoplasmic domains are a unifying feature within the family. However, the extracellular domain sequences are molecule-specific, implying that different syndecans have evolved to carry out similar, but non-identical, functions. While all four syndecans have been implicated in regulation of the cytoskeleton, their roles are clearly complex. Recent developments indicate that the closely related syndecan-2 and -4 have separable functions, though both bind a number of ligands through their heparan sulfate chains. The specification of these activities is probably core protein related, but is it due to a distinct expression pattern or molecule-specific regulatory mechanisms? Although there is not yet enough data to provide unambiguous answers, here we shall review the known functions and regulatory mechanisms of syndecan-2 and -4.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Adhesion / physiology
  • Cell Division / physiology
  • Cytoskeleton / metabolism
  • Growth Substances / metabolism
  • Humans
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / metabolism*
  • Neovascularization, Physiologic
  • Protein Conformation
  • Proteoglycans / chemistry
  • Proteoglycans / metabolism*
  • Syndecan-2
  • Syndecan-4
  • Tissue Distribution


  • Growth Substances
  • Membrane Glycoproteins
  • Proteoglycans
  • SDC2 protein, human
  • SDC4 protein, human
  • Syndecan-4
  • Syndecan-2