Figure 14.

This diagram shows the molecular components of the VMA we have begun to characterize. The αvβ3-integrin associates with a laminin subunit at the core of the structure. We speculate that vimentin-type intermediate filaments interact with the VMA via an association with plectin (Wiche et al., 1982; Steinböck et al., 2000). Because plectin possesses an actin-binding motif, plectin, together with focal contact proteins such as vinculin, may be involved in mediating microfilament (MF) bundle-cell surface association (Elliot et al., 1997). The protein that links vinculin to the αvβ3-integrin may be α-actinin (Simon and Burridge, 1994), whereas the identity of the protein that links plectin to αvβ3 is yet to be determined.