Transient anchorage of cross-linked glycosyl-phosphatidylinositol-anchored proteins depends on cholesterol, Src family kinases, caveolin, and phosphoinositides

J Cell Biol. 2006 Oct 9;175(1):169-78. doi: 10.1083/jcb.200512116.

Abstract

How outer leaflet plasma membrane components, including glycosyl-phosphatidylinositol-anchored proteins (GPIAPs), transmit signals to the cell interior is an open question in membrane biology. By deliberately cross-linking several GPIAPs under antibody-conjugated 40-nm gold particles, transient anchorage of the gold particle-induced clusters of both Thy-1 and CD73, a 5' exonucleotidase, occurred for periods ranging from 300 ms to 10 s in fibroblasts. Transient anchorage was abolished by cholesterol depletion, addition of the Src family kinase (SFK) inhibitor PP2, or in Src-Yes-Fyn knockout cells. Caveolin-1 knockout cells exhibited a reduced transient anchorage time, suggesting the partial participation of caveolin-1. In contrast, a transmembrane protein, the cystic fibrosis transmembrane conductance regulator, exhibited transient anchorage that occurred without deliberately enhanced cross-linking; moreover, it was only slightly inhibited by cholesterol depletion or SFK inhibition and depended completely on the interaction of its PDZ-binding domain with the cytoskeletal adaptor EBP50. We propose that cross-linked GPIAPs become transiently anchored via a cholesterol-dependent SFK-regulatable linkage between a transmembrane cluster sensor and the cytoskeleton.

Publication types

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

MeSH terms

  • 5'-Nucleotidase / metabolism
  • Animals
  • Caveolin 1 / genetics
  • Caveolin 1 / physiology*
  • Cells, Cultured
  • Cholesterol / physiology*
  • Cystic Fibrosis Transmembrane Conductance Regulator / chemistry
  • Cystic Fibrosis Transmembrane Conductance Regulator / metabolism
  • Cytoskeleton / metabolism
  • Glycosylphosphatidylinositols / metabolism*
  • Gold / analysis
  • Humans
  • Membrane Proteins / metabolism*
  • Mice
  • Models, Biological
  • Nanoparticles / analysis
  • Phosphatidylinositols / genetics
  • Phosphatidylinositols / physiology*
  • Protein Structure, Tertiary
  • Thy-1 Antigens / metabolism
  • src-Family Kinases / antagonists & inhibitors
  • src-Family Kinases / genetics
  • src-Family Kinases / physiology*

Substances

  • Caveolin 1
  • Glycosylphosphatidylinositols
  • Membrane Proteins
  • Phosphatidylinositols
  • Thy-1 Antigens
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Gold
  • Cholesterol
  • src-Family Kinases
  • 5'-Nucleotidase