Dynamic Regulation of Activated Leukocyte Cell Adhesion Molecule–mediated Homotypic Cell Adhesion through the Actin CytoskeletonV⃞
AUTOR(ES)
Nelissen, Judith M. D. T.
FONTE
The American Society for Cell Biology
RESUMO
Restricted expression of activated leukocyte cell adhesion molecule (ALCAM) by hematopoietic cells suggests an important role in the immune system and hematopoiesis. To get insight into the mechanisms that control ALCAM-mediated adhesion we have investigated homotypic ALCAM–ALCAM interactions. Here, we demonstrate that the cytoskeleton regulates ALCAM-mediated cell adhesion because inhibition of actin polymerization by cytochalasin D (CytD) strongly induces homotypic ALCAM–ALCAM interactions. This induction of cell adhesion is likely due to clustering of ALCAM at the cell surface, which is observed after CytD treatment. Single-particle tracking demonstrated that the lateral mobility of ALCAM in the cell membrane is increased 30-fold after CytD treatment. In contrast, both surface distribution and adhesion of a glycosylphosphatidylinositol (GPI)-anchored ALCAM mutant are insensitive to CytD, despite the increase in lateral mobility of GPI-ALCAM upon CytD treatment. This demonstrates that clustering of ALCAM is essential for cell adhesion, whereas enhanced diffusion of ALCAM alone is not sufficient for cluster formation. In addition, upon ligand binding, both free diffusion and the freely dragged distance of wild-type ALCAM, but not of GPI-ALCAM, are reduced over time, suggesting strengthening of the cytoskeleton linkage. From these findings we conclude that activation of ALCAM-mediated adhesion is dynamically regulated through actin cytoskeleton-dependent clustering.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=14903Documentos Relacionados
- NEW EMBO MEMBER’S REVIEW: Changing neighbours, changing behaviour: cell adhesion molecule-mediated signalling during tumour progression
- Phosphorylation-dependent Localization of Microtubule-associated Protein MAP2c to the Actin CytoskeletonV⃞
- The Saccharomyces cerevisiae Calponin/Transgelin Homolog Scp1 Functions with Fimbrin to Regulate Stability and Organization of the Actin CytoskeletonV⃞
- A Dynamic Actin Cytoskeleton Functions at Multiple Stages of Clathrin-mediated EndocytosisV⃞
- Three-dimensional Imaging of the Yeast Actin Cytoskeleton through the Budding Cell CycleV⃞