Figure 7: PlexA4 interacts with GluA2 through its IPT domain.

(a) Structure of PlexAs and schematic representation of constructed PlexAs mutant. PlexAs contain signal peptides, sema domain, three PSI (domains found in plexin, semaphorin and integrin) domains, three IPT (immunoglobulin-like plexin transcription factor) domains, transmembrane domain and cytosolic domain. Abbreviations are as follows: Full, full length; DN, dominant negative; IPT, three IPT; Δect, lacking the entire ectodomain; ΔIPT, lacking three IPT ectodomain. (b) EGFP-tagged GluA2 interacted with full-length or IPT domain of PlexA4-Myc. (c) EGFP-tagged GluA2 weakly interacted with ΔIPT mutant of PlexA4-Myc. (d) Flag-tagged NRP1 interacted with full length, but not IPT domain, of PlexA4-Myc. (e) GluA2 and PlexA4 were co-immunoprecipitated from rat brain lysates. (f) A Sema3A-induced increase in the number of PlexA4–GluA2 interacting signals detected by in situ PLA technology in cell body followed by an increase in dendrites. The mean number of PlexA4-GluA2 interacting signals per 10 μm2 (soma) or 10 μm (dendrite) is shown in g (n=45 neurons from three independent cultures). Scale bar, 20 μm. *P<0.01 by ANOVA compared with 0 min. Data are presented as mean±s.e.m. Full scan of western blot of b–e are shown in Supplementary Fig. 7a–g.