Related Experiment Video
Updated: May 20, 2026

Assay to Measure Nucleocytoplasmic Transport in Real Time within Motor Neuron-like NSC-34 Cells
Published on: May 16, 2017
Rho guanine nucleotide exchange factor is an NFL mRNA destabilizing factor that forms cytoplasmic inclusions in
Cristian A Droppelmann1, Brian A Keller, Danae Campos-Melo
1Molecular Brain Research Group, Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.
Abstract:
Amyotrophic lateral sclerosis (ALS) is an adult-onset progressive disorder of unknown etiology characterized by the selective degeneration of motor neurons. Recent evidence supports the hypothesis that alterations in RNA metabolism in motor neurons can explain the development of protein inclusions, including neurofilamentous aggregates, observed in this pathology. In mice, p190RhoGEF, a guanine nucleotide exchange factor, is involved in neurofilament protein aggregation in an RNA-triggered transgenic model of motor neuron disease. Here, we observed that rho guanine nucleotide exchange factor (RGNEF), the human homologue of p190RhoGEF, binds low molecular weight neurofilament mRNA and affects its stability via 3' untranslated region destabilization. We observed that the overexpression of RGNEF in a stable cell line significantly decreased the level of low molecular weight neurofilament protein. Furthermore, we observed RGNEF cytoplasmic inclusions in ALS spinal motor neurons that colocalized with ubiquitin, p62/sequestosome-1, and TAR (trans-active regulatory) DNA-binding protein 43 (TDP-43). Our results provide further evidence that RNA metabolism pathways are integral to ALS pathology. This is also the first described link between ALS and an RNA binding protein with aggregate formation that is also a central cell signaling pathway molecule.
Related Concept Videos
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
GTPases and their Regulation
Large G-proteins, also known...
Directionality of Nuclear Transport
Activation and Inactivation of G Proteins
Rab Cascades

