Regulation of nerve growth and patterning by cell surface protein disulphide isomerase
- University of Cambridge, United Kingdom
Abstract
Contact repulsion of growing axons is an essential mechanism for spinal nerve patterning. In birds and mammals the embryonic somites generate a linear series of impenetrable barriers, forcing axon growth cones to traverse one half of each somite as they extend towards their body targets. This study shows that protein disulphide isomerase provides a key component of these barriers, mediating contact repulsion at the cell surface in chick half-somites. Repulsion is reduced both in vivo and in vitro by a range of methods that inhibit enzyme activity. The activity is critical in initiating a nitric oxide/S-nitrosylation-dependent signal transduction pathway that regulates the growth cone cytoskeleton. Rat forebrain grey matter extracts contain a similar activity, and the enzyme is expressed at the surface of cultured human astrocytic cells and rat cortical astrocytes. We suggest this system is co-opted in the brain to counteract and regulate aberrant nerve terminal growth.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files.
Article and author information
Author details
Funding
Medical Research Council
- Geoffrey MW Cook
- Roger J Keynes
Wellcome
- Geoffrey MW Cook
- Roger J Keynes
Spinal Research
- Julia Schaeffer
Trinity College, University of Cambridge
- Roger J Keynes
University of Cambridge
- Geoffrey MW Cook
- Catia Sousa
- Julia Schaeffer
- Katharine Wiles
- Prem Jareonsettasin
- Asanish Kalyanasundaram
- Eleanor Walder
- Catharina Casper
- Serena Patel
- Pei Wei Chua
- Gioia Riboni-Verri
- Mansoor Raza
- Nol Swaddiwudhipong
- Andrew Hui
- Ameer Abdullah
- Saj Wajed
- Roger J Keynes
Rosetrees Trust
- Geoffrey MW Cook
- Julia Schaeffer
- Roger J Keynes
The Anatomical Society
- Eleanor Walder
Amgen Foundation Summer Scholarship
- Gioia Riboni-Verri
The authors declare that the funders provided research equipment and laboratory consumables, as well as salary support for Julia Schaeffer, Eleanor Walder and Gioia Riboni-Verri.
Ethics
Animal experimentation: Chick embryos were used for this work, and all experiments were carried out at earlier developmental stages than those that require ethical approval.
Copyright
© 2020, Cook 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.
Metrics
-
- 1,286
- views
-
- 186
- downloads
-
- 4
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Regulation of nerve growth and patterning by cell surface protein disulphide isomerase
eLife 9:e54612.
https://doi.org/10.7554/eLife.54612
Further reading
-
- Cell Biology
- Developmental Biology
The formation of large endolysosomal structures in unfertilized eggs ensures that lysosomes remain dormant before fertilization, and then shift into clean-up mode after the egg-to-embryo transition.
-
- Developmental Biology
Ribonucleoprotein (RNP) granules are membraneless electron-dense structures rich in RNAs and proteins, and involved in various cellular processes. Two RNP granules in male germ cells, intermitochondrial cement and the chromatoid body (CB), are associated with PIWI-interacting RNAs (piRNAs) and are required for transposon silencing and spermatogenesis. Other RNP granules in male germ cells, the reticulated body and CB remnants, are also essential for spermiogenesis. In this study, we disrupted FBXO24, a testis-enriched F-box protein, in mice and found numerous membraneless electron-dense granules accumulated in sperm flagella. Fbxo24 knockout (KO) mice exhibited malformed flagellar structures, impaired sperm motility, and male infertility, likely due to the accumulation of abnormal granules. The amount and localization of known RNP granule-related proteins were not disrupted in Fbxo24 KO mice, suggesting that the accumulated granules were distinct from known RNP granules. Further studies revealed that RNAs and two importins, IPO5 and KPNB1, abnormally accumulated in Fbxo24 KO spermatozoa and that FBXO24 could ubiquitinate IPO5. In addition, IPO5 and KPNB1 were recruited to stress granules, RNP complexes, when cells were treated with oxidative stress or a proteasome inhibitor. These results suggest that FBXO24 is involved in the degradation of IPO5, disruption of which may lead to the accumulation of abnormal RNP granules in sperm flagella.
