The adenomatous polyposis coli protein: in the limelight out at the edge

Truncation mutations in the adenomatous polyposis coli protein (APC) are re sponsible for familial and sporadic colonic tumours. APC is best known for its role in regulating beta -catenin, an important mediator of cell adhesio n and a transcriptional activator. However, recent studies indicate that AP C has additional roles in cytoskeletal regulation. It binds to microtubules directly and indirectly. Furthermore, indirect connections between APC and the actin cytoskeleton have also been described. Here, we integrate recent information describing the association between APC and the cytoskeleton to illustrate how this multifaceted protein might link different cytoskeletal elements to each other and to cellular signaling pathways.