Annexin V binds to the actin-based cytoskeleton at the plasma membrane of activated platelets

Exp Cell Res. 1999 Aug 25;251(1):185-93. doi: 10.1006/excr.1999.4553.

Abstract

Immunocytochemical studies demonstrate that annexin V relocates to the plasma membranes of intact stimulated blood platelets. Anti-annexin V antibodies label the cytoplasmic side of the substrate-adherent plasma membrane of mechanically unroofed, glass-activated platelets and colocalize with actin. In addition, crosslinking experiments using detergent-solubilized membranes of activated platelets have identified an 85-kDa complex containing annexin V. The 85-kDa complex is also recognized by antibodies against actin, suggesting that annexin V interacts with actin. In addition, annexin V was found to associate with filamentous actin in the presence of millimolar Ca(2+). Annexin V was also shown by immunofluorescence microscopy to be associated with platelet cytoskeletons, colocalizing with actin in the presence of micromolar Ca(2+). These findings provide the first evidence for annexin V binding to the plasma membrane and to the actin-based cytoskeleton in activated platelets and indicate that annexin V may function in both cytoskeletal and membrane domains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / drug effects
  • Actin Cytoskeleton / metabolism
  • Actins / metabolism*
  • Annexin A5 / metabolism*
  • Blood Platelets / drug effects
  • Blood Platelets / metabolism*
  • Blood Platelets / physiology
  • Blood Platelets / ultrastructure
  • Calcium / pharmacology
  • Cell Adhesion / drug effects
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism*
  • Cell Size / drug effects
  • Cross-Linking Reagents
  • Cytochalasins / pharmacology
  • Cytoskeleton / drug effects
  • Cytoskeleton / metabolism*
  • Egtazic Acid / pharmacology
  • Fixatives
  • Fluorescent Antibody Technique
  • Glass
  • Humans
  • Molecular Weight
  • Platelet Activation* / drug effects
  • Protein Binding / drug effects
  • Pseudopodia / drug effects

Substances

  • Actins
  • Annexin A5
  • Cross-Linking Reagents
  • Cytochalasins
  • Fixatives
  • cytochalasin E
  • Egtazic Acid
  • Calcium