ABSTRACT
Cbenorhabditis elegans has only one beta integrin chain, called PAT-3, and two alpha integrin chains, called PAT-2 and INA-1. C. elegans integrine are essential for muscle anchoring to the epidermis, cell migration, axon outgrowth and fasciculation, and epi thelial morphogenesis. Genetic analysis o f this simple integrin repertoire has led to the identi fication o f protein complexes that interact with integrins during these developmental pro cesses. We discuss how the analysis o f muscle anchoring, which is mediated by the PAT-2/ PAT-3 heterodimer, has become a model to understand the stepwise assembly o f proteins such as ILK, actopaxin, Pinch, Kindlin or vinculin at focal adhesions. Likewise, the analysis o f cell migration and axon outgrowth is a model to investigate the signaling events involved in medi ating adhesion to the lam inin-binding INA-l/PAT-3 heterodimer. In particular, it has revealed that the serine/threonine kinase N IK acts in the same process as integrins during axon out growth.
