Bridging the gap

Abstract

A new study reveals that a protein called talin forms a vital link between microtubules and focal adhesions at the surface of cells.

Keywords: biophysics; cell biology; focal adhesion; human; microtubule; structural biology; talin.

Figure 1.. The role of the talin-KANK1 interaction in controlling the architecture of microtubules.

(A) The cortical microtubule stabilization complex (CMSC) is a collection of proteins that associates with the plasma membrane (PM) of human cells (top panel). Individual components of the complex are shown in different shades of blue, while microtubule end-binding proteins are shown in light green. Focal adhesions are multi-protein assemblies containing integrins (shown in red) that connect the cell to the surrounding extracellular matrix (ECM). Talin and vinculin (shown in yellow and purple, respectively) link integrins to the actin cytoskeleton. Bouchet et al. report that a mechanically sensitive adaptor protein talin must interact with another protein, called KANK1 (orange), to link the CMSC to focal adhesions. This interaction prevents microtubules from growing too much at the edge of the cell (bottom panel). The green arrows depict growing microtubules, and the speed of microtubule growth is depicted by the size of the arrowhead. (B) If the talin-KANK1 interaction is disrupted, CMSC components are not recruited to focal adhesions and the CMSC cannot capture microtubules (top panel). Disrupting the talin-KANK1 interaction does not, however, stop focal adhesions from assembling. Disrupting the talin-KANK1 interaction leads to the microtubules growing faster and becoming disorganized at the cell’s edge (bottom panel).