The collagen receptor uPARAP/Endo180

Front Biosci (Landmark Ed). 2009 Jan 1;14:2103-14. doi: 10.2741/3365.

Abstract

The uPAR-associated protein (uPARAP/Endo180), a type-1 membrane protein belonging to the mannose receptor family, is an endocytic receptor for collagen. Through this endocytic function, the protein takes part in a previously unrecognized mechanism of collagen turnover. uPARAP/Endo180 can bind and internalize both intact and partially degraded collagens. In some turnover pathways, the function of the receptor probably involves an interplay with certain matrix-degrading proteases whereas, in other physiological processes, redundant mechanisms involving both endocytic and pericellular collagenolysis seem to operate in parallel. On certain cell types, uPARAP/Endo180 occurs in a complex with the urokinase plasminogen activator receptor (uPAR) where it seems to fulfill other functions in addition to collagenolysis. uPARAP/Endo180 is expressed on various mesenchymal cells, including subpopulations of fibroblasts, osteoblasts and chondrocytes, generally in conjunction with matrix turnover and collagenolysis. A striking expression is found in developing bone where the collagenolytic function of uPARAP/Endo180 is one of the rate-limiting steps in growth. In murine breast tumors, the endocytic function of the receptor in collagen breakdown seems to be involved in invasive tumor growth.

Publication types

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

MeSH terms

  • Humans
  • Mannose-Binding Lectins / chemistry
  • Mannose-Binding Lectins / metabolism*
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / metabolism*
  • Protein Conformation
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / metabolism*
  • Receptors, Mitogen / chemistry
  • Receptors, Mitogen / metabolism*

Substances

  • Endo180
  • MRC2 protein, human
  • Mannose-Binding Lectins
  • Membrane Glycoproteins
  • Receptors, Cell Surface
  • Receptors, Mitogen