NgR1 forms ternary complex with PlexinA2 and CRMP2. A, HEK293T cells were transfected with FLAG-NgR1 and Myc-CRMP2 or with HA-PlexinA2. Myc immunoprecipitates were immunoblotted for NgR1, HA, and Myc. TCL, Total cell lysates. B, C, Twenty-one DIV cortical neurons from WT or PlexinA2−/− were stimulated without or with Nogo22 (100 nm) for 5 min and then lysed. The lysate was immunoprecipitated with anti-NgR1 antibody and immunoblotted for CRMP2, NgR1, and PlexinA2. C, The graph shows the quantification of CRMP2 protein level in the immunoprecipitates normalized to total cell lysate (n = 3). *p < 0.05, one-way ANOVA followed by Tukey's test. D, Schematic model of Nogo-A-induced ternary complex of NgR1, PlexinA2 and CRMP2.