Human Rab7 mutation mimics features of Charcot-Marie-Tooth neuropathy type 2B in Drosophila.

Abstract

Charcot-Marie-Tooth disease type 2B (CMT2B) is an inherited axonal peripheral neuropathy. It is characterised by prominent sensory loss, often complicated by severe ulcero-mutilations of toes or feet, and variable motor involvement. Missense mutations in RAB7A, the gene encoding the small GTPase Rab7, cause CMT2B and increase Rab7 activity. Rab7 is ubiquitously expressed and is involved in degradation through the lysosomal pathway. In the neurons, Rab7 plays a role in the long-range retrograde transport of signalling endosomes in the axons. Here we developed the first animal model of CMT2B, modelling one of the mutations (L129F) in Drosophila melanogaster. Behavioural assays show that this model recapitulates several hallmarks of the human disease. Upon expression of mutant Rab7 in the sensory neurons, larvae present with a reduction of temperature and pain perception. Furthermore, the larvae exhibit a crawling defect when the mutant protein is expressed in the motor neurons. Analysis of axonal transport of Rab7 positive vesicles in sensory neurons of Drosophila larvae and in neurites of mammalian neuroblastoma cells demonstrates that mutant vesicles pause less than their wild-type counterparts. This latter finding indicates that alterations in vesicle transport might contribute to the pathomechanism of CMT2B.

• Authors: Katrien Janssens, Sofie Goethals, Derek Atkinson, Biljana Ermanoska, Erik Fransen, Albena Jordanova, Michaela Auer-Grumbach, Bob Asselbergh, Vincent Timmerman
• Journal: Neurobiology of disease (Neurobiol Dis) Vol. 65 Pg. 211-9 (May 2014) ISSN: 1095-953X [Electronic] United States
• PMID: 24521780 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Drosophila Proteins
• rab7 GTP-Binding Proteins
• rab7 GTP-binding proteins, human
• Green Fluorescent Proteins
• rab GTP-Binding Proteins

Topics

• Animals
• Animals, Genetically Modified
• Behavior, Animal (physiology)
• Cell Differentiation
• Cell Line, Transformed
• Charcot-Marie-Tooth Disease (genetics, physiopathology)
• Dendrites (pathology)
• Disease Models, Animal
• Drosophila
• Drosophila Proteins (genetics)
• Green Fluorescent Proteins (genetics, metabolism)
• Humans
• Laminopathies
• Larva
• Male
• Motor Activity (genetics)
• Mutation (genetics)
• Neuroblastoma (pathology)
• Sensory Receptor Cells (pathology)
• Transduction, Genetic
• rab GTP-Binding Proteins (genetics)
• rab7 GTP-Binding Proteins