RRC ID 76514
Author Jardin N, Giudicelli F, Ten Martín D, Vitrac A, De Gois S, Allison R, Houart C, Reid E, Hazan J, Fassier C.
Title BMP- and neuropilin 1-mediated motor axon navigation relies on spastin alternative translation.
Journal Development
Abstract Functional analyses of genes responsible for neurodegenerative disorders have unveiled crucial links between neurodegenerative processes and key developmental signalling pathways. Mutations in SPG4-encoding spastin cause hereditary spastic paraplegia (HSP). Spastin is involved in diverse cellular processes that couple microtubule severing to membrane remodelling. Two main spastin isoforms are synthesised from alternative translational start sites (M1 and M87). However, their specific roles in neuronal development and homeostasis remain largely unknown. To selectively unravel their neuronal function, we blocked spastin synthesis from each initiation codon during zebrafish development and performed rescue analyses. The knockdown of each isoform led to different motor neuron and locomotion defects, which were not rescued by the selective expression of the other isoform. Notably, both morphant neuronal phenotypes were observed in a CRISPR/Cas9 spastin mutant. We next showed that M1 spastin, together with HSP proteins atlastin 1 and NIPA1, drives motor axon targeting by repressing BMP signalling, whereas M87 spastin acts downstream of neuropilin 1 to control motor neuron migration. Our data therefore suggest that defective BMP and neuropilin 1 signalling may contribute to the motor phenotype in a vertebrate model of spastin depletion.
Volume 145(17)
Published 2018-9-12
DOI 10.1242/dev.162701
PII dev.162701
PMID 30082270
PMC PMC6141775
MeSH Animals Axons / metabolism Bone Morphogenetic Proteins / metabolism* COS Cells CRISPR-Cas Systems / genetics Cell Line Cell Movement / genetics Chlorocebus aethiops GTP-Binding Proteins / metabolism Gene Knockout Techniques Humans Membrane Proteins / metabolism Motor Neurons / cytology* Neuropilin-1 / metabolism* Protein Isoforms / genetics Spastic Paraplegia, Hereditary / genetics Spastin / biosynthesis Spastin / genetics* Zebrafish / embryology* Zebrafish Proteins / biosynthesis Zebrafish Proteins / genetics*
IF 5.611
Resource
Zebrafish mnGFF7, UAS:GFP