Biology Reference
In-Depth Information
The Role of Talin and
Myosin VII in Adhesion -
A FERM Connection
Margaret A. Titus
Cell-surface and cell-cell contact is mediated by surface receptors that are
intimately linked to the actin cytoskeleton. A number of actin binding and
signalling proteins are important for establishing these adhesions and it has
recently been shown that unconventional myosins also play a role.
Dictyostelium cells lacking a class VII myosin adhere poorly to surfaces and
are defective in calcium-dependent cell-cell adhesion, a phenotype strikingly
similar to talin null cells. Both proteins bind actin and possess one or more
FERM domains, a module found in a large number of adhesion proteins. The
conserved role of talin throughout phylogeny and the potential shared
function between myosin VII and the closely related class X myosins of
mammals suggests that lessons learned about Dictyostelium adhesion will
provide insight into the conserved function for these proteins.
Adhesion between a cell and the substrate is essential for e
cient, directed cell
migration and phagocytosis and cell-cell adhesion is critically important for
morphogenesis during multicellular development. Engagement of cell surface
receptors by extracellular ligands results in the stimulation of cell signalling
pathways that ultimately activate the cytoskeleton (Geiger et al., 2001). This,
in turn, drives the extension of an actin-rich protrusion such as a
lamellipodium or phagocytic cup in the direction of the contact or results in
