Functional divergence of Plexin B structural motifs in distinct steps of Drosophila olfactory circuit assembly
Abstract
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., 2018). 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.
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All data generated or analysed during this study are included in the manuscript and supporting files.
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Funding
Howard Hughes Medical Institute
- Liqun Luo
National Institutes of Health (R01-DC005982)
- Liqun Luo
The Yingwei Cui and Hui Zhao Neuroscience Fund
- Liqun Luo
Stanford University (Bio-X Undergraduate Summer Research Program)
- Ricardo Guajardo
Stanford University (Stanford Undergraduate Advising and Research Major Grant)
- Ricardo Guajardo
Stanford University (Bio-X Bowes Interdisciplinary Graduate Fellowship)
- Shuo Han
Genentech Foundation (Genentech Foundation Predoctoral Fellowship)
- Jiefu Li
Stanford University (Vanessa Kong-Kerzner Graduate Fellowship)
- Jiefu Li
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Kristin Scott, University of California, Berkeley, United States
Version history
- Received: May 22, 2019
- Accepted: June 20, 2019
- Accepted Manuscript published: June 21, 2019 (version 1)
- Version of Record published: June 27, 2019 (version 2)
Copyright
© 2019, Guajardo et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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