TY - JOUR TI - Functional divergence of Plexin B structural motifs in distinct steps of Drosophila olfactory circuit assembly AU - Guajardo, Ricardo AU - Luginbuhl, David J AU - Han, Shuo AU - Luo, Liqun AU - Li, Jiefu A2 - Scott, Kristin A2 - VijayRaghavan, K A2 - Chihara, Takahiro A2 - Ye, Bing VL - 8 PY - 2019 DA - 2019/06/21 SP - e48594 C1 - eLife 2019;8:e48594 DO - 10.7554/eLife.48594 UR - https://doi.org/10.7554/eLife.48594 AB - Plexins exhibit multitudinous, evolutionarily conserved functions in neural development. How Plexins employ their diverse structural motifs in vivo to perform distinct roles is unclear. We previously reported that Plexin B (PlexB) controls multiple steps during the assembly of the Drosophila olfactory circuit (Li et al., 2018b). Here, we systematically mutagenized structural motifs of PlexB and examined the function of these variants in these multiple steps: axon fasciculation, trajectory choice, and synaptic partner selection. We found that the extracellular Sema domain is essential for all three steps, the catalytic site of the intracellular RapGAP is engaged in none, and the intracellular GTPase-binding motifs are essential for trajectory choice and synaptic partner selection, but are dispensable for fasciculation. Moreover, extracellular PlexB cleavage serves as a regulatory mechanism of PlexB signaling. Thus, the divergent roles of PlexB motifs in distinct steps of neural development contribute to its functional versatility in neural circuit assembly. KW - Plexin KW - olfactory circuit KW - neural wiring JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -