@article{TEXTUAL, recid = {11113}, author = {Priest, Jessica M. and Nichols, Ev L. and Smock, Robert G. and Hopkins, Jesse B. and Mendoza, Juan L. and Meijers, ROb and Shen, Kang and Özkan, Engin}, title = {Structural insights into the formation of repulsive netrin guidance complexes}, journal = {Science Advances}, address = {2024-02-16}, number = {TEXTUAL}, abstract = {Netrins dictate attractive and repulsive responses during axon growth and cell migration, where the presence of the receptor Uncoordinated-5 (UNC-5) on target cells results in repulsion. Here, we showed that UNC-5 is a heparin-binding protein, determined its structure bound to a heparin fragment, and could modulate UNC-5–heparin affinity using a directed evolution platform or structure-based rational design. We demonstrated that UNC-5 and UNC-6/netrin form a large, stable, and rigid complex in the presence of heparin, and heparin and UNC-5 exclude the attractive UNC-40/DCC receptor from binding to UNC-6/netrin to a large extent. Caenorhabditis elegans with a heparin-binding–deficient UNC-5 fail to establish proper gonad morphology due to abrogated cell migration, which relies on repulsive UNC-5 signaling in response to UNC-6. Combining UNC-5 mutations targeting heparin and UNC-6/netrin contacts results in complete cell migration and axon guidance defects. Our findings establish repulsive netrin responses to be mediated through a glycosaminoglycan-regulated macromolecular complex.}, url = {http://knowledge.uchicago.edu/record/11113}, }