Plexins and neuropilins regulate integrin conformation and trafficking in endothelial cells

Integrin the are major extracellular matrix receptors and their functional state with respect to the affinity for extracellular matrix proteins is pivotal for their biological activities in physiologic and pathological settings. Integrins' machinery depends on the dynamic regulation of their adhesive function in space and time. In cells, integrins exist in different conformations which determine their affinity for extracellular matrix proteins and are continuously endocytosed, trafficked through endosomal compartments, and recycled back to the plasma membrane. Therefore real-time modulation of cell - extracellular matrix adhesion can result from two interconnected phenomena: the regulation of integrin conformation and traffic in response to extracellular stimuli. This review summarizes recent data highlighting the different mechanisms by which semaphorins and their receptors plexins and neuropilins regulate integrin functions in vascular system. Domenico Ribatti (Ed.) All rights reserved -