Nitric oxide-mediated posttranslational modifications control neurotransmitter release by modulating complexin farnesylation and enhancing its clamping ability

Butcher, Adrian; Robinson, Susan W.; Bourgognon, Julie-Myrtille; Spiers, Jereme G.; Breda, Carlo; Morone, Nobuhiro; Mistry, Raj; Campesan, Susanna; Challiss, R. A. John; Giorgini, Flaviano; Mallucci, Giovanna R.; Smith, Tim M.; Dinsdale, David; Guerra-Martin, Maria; Steinert, Joern R.

Abstract

Nitric oxide (NO) regulates neuronal function and thus is critical for tuning neuronal communication. Mechanisms by which NO modulates protein function and interaction include posttranslational modifications (PTMs) such as S-nitrosylation. Importantly, cross signaling between S-nitrosylation and prenylation can have major regulatory potential. However, the exact protein targets and resulting changes in function remain elusive. Here, we interrogated the role of NO-dependent PTMs and farnesylation in synaptic transmission. We found that NO compromises synaptic function at the Drosophila neuromuscular junction (NMJ) in a cGMP-independent manner. NO suppressed release and reduced the size of available vesicle pools, which was reversed by glutathione (GSH) and occluded by genetic up-regulation of GSH-generating and de-nitrosylating glutamate-cysteine-ligase and S-nitroso-glutathione reductase activities. Enhanced nitrergic activity led to S-nitrosylation of the fusion-clamp protein complexin (cpx) and altered its membrane association and interactions with active zone (AZ) and soluble N-ethyl-maleimide-sensitive fusion protein Attachment Protein Receptor (SNARE) proteins. Furthermore, genetic and pharmacological suppression of farnesylation and a nitrosylation mimetic mutant of cpx induced identical physiological and localization phenotypes as caused by NO. Together, our data provide evidence for a novel physiological nitrergic molecular switch involving S-nitrosylation, which reversibly suppresses farnesylation and thereby enhances the net-clamping function of cpx. These data illustrate a new mechanistic signaling pathway by which regulation of farnesylation can fine-tune synaptic release.

Citation

Butcher, A., Robinson, S. W., Bourgognon, J.-M., Spiers, J. G., Breda, C., Morone, N., Mistry, R., Campesan, S., Challiss, R. A. J., Giorgini, F., Mallucci, G. R., Smith, T. M., Dinsdale, D., Guerra-Martin, M., & Steinert, J. R. (2018). Nitric oxide-mediated posttranslational modifications control neurotransmitter release by modulating complexin farnesylation and enhancing its clamping ability. PLoS Biology, 16(4), Article e2003611. https://doi.org/10.1371/journal.pbio.2003611

• Journal Article Type: Article
• Acceptance Date: Feb 20, 2018
• Online Publication Date: Apr 9, 2018
• Publication Date: Apr 9, 2018
• Deposit Date: Jun 17, 2020
• Journal: PLOS Biology
• Print ISSN: 1544-9173
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 16
• Issue: 4
• Article Number: e2003611
• DOI: https://doi.org/10.1371/journal.pbio.2003611
• Public URL: https://nottingham-repository.worktribe.com/output/4668022
• Publisher URL: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2003611