Mahabaleshwar, H., Tarbashevich, K., Nowak, M., Brand, M., and Raz, E. (2012) beta-arrestin control of late endosomal sorting facilitates decoy receptor function and chemokine gradient formation. Development (Cambridge, England). 139(16):2897-2902.
A crucial regulator of Cxcl12 is the decoy receptor Cxcr7, which controls the level of the chemokine in the tissue. The molecular
mechanisms that enable Cxcr7 to function as an efficient molecular sink are not known. Using zebrafish primordial germ cells
as a model, we identify a novel role for β-arrestins in controlling the intracellular trafficking of Cxcr7. β-arrestins facilitate
the recycling of Cxcr7 from late endosomal compartments back to the plasma membrane, whereas the internalized ligand undergoes
lysosomal degradation. β-arrestins thus function in regulating chemokine gradient formation, allowing responding cells to
discriminate between alternative migration targets in vivo.