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Ukken FP, Bruckner JJ, Weir KL, Hope SJ, Sison SL, Birschbach RM, Hicks L, Taylor KL, Dent EW, Gonsalvez GB, O'Connor-Giles KM. BAR-SH3 sorting nexins are conserved interacting proteins of Nervous wreck that organize synapses and promote neurotransmission. J Cell Sci 2015; 129:166-77. [PMID: 26567222 PMCID: PMC4732300 DOI: 10.1242/jcs.178699] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 11/11/2015] [Indexed: 12/13/2022] Open
Abstract
Nervous wreck (Nwk) is a conserved F-BAR protein that attenuates synaptic growth and promotes synaptic function in Drosophila. In an effort to understand how Nwk carries out its dual roles, we isolated interacting proteins using mass spectrometry. We report a conserved interaction between Nwk proteins and BAR-SH3 sorting nexins, a family of membrane-binding proteins implicated in diverse intracellular trafficking processes. In mammalian cells, BAR-SH3 sorting nexins induce plasma membrane tubules that localize NWK2, consistent with a possible functional interaction during the early stages of endocytic trafficking. To study the role of BAR-SH3 sorting nexins in vivo, we took advantage of the lack of genetic redundancy in Drosophila and employed CRISPR-based genome engineering to generate null and endogenously tagged alleles of SH3PX1. SH3PX1 localizes to neuromuscular junctions where it regulates synaptic ultrastructure, but not synapse number. Consistently, neurotransmitter release was significantly diminished in SH3PX1 mutants. Double-mutant and tissue-specific-rescue experiments indicate that SH3PX1 promotes neurotransmitter release presynaptically, at least in part through functional interactions with Nwk, and might act to distinguish the roles of Nwk in regulating synaptic growth and function.
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Affiliation(s)
- Fiona P Ukken
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Joseph J Bruckner
- Cell and Molecular Biology Training Program, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Kurt L Weir
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Sarah J Hope
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Samantha L Sison
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Ryan M Birschbach
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Lawrence Hicks
- Cellular Biology and Anatomy, Georgia Regents University, Augusta, GA 30912, USA
| | - Kendra L Taylor
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Erik W Dent
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705, USA Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Graydon B Gonsalvez
- Cellular Biology and Anatomy, Georgia Regents University, Augusta, GA 30912, USA
| | - Kate M O'Connor-Giles
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706, USA Cell and Molecular Biology Training Program, University of Wisconsin-Madison, Madison, WI 53706, USA Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
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