C9ORF72 interaction with cofilin modulates actin dynamics in motor neurons
Research output: Contribution to journal › Journal article › Research › peer-review
Rajeeve Sivadasan, Daniel Hornburg, Carsten Drepper, Nicolas Frank, Sibylle Jablonka, Anna Hansel, Xenia Lojewski, Jared Sterneckert, Andreas Hermann, Pamela J Shaw, Paul G Ince, Matthias Mann, Felix Meissner, Michael Sendtner
Intronic hexanucleotide expansions in C9ORF72 are common in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, but it is unknown whether loss of function, toxicity by the expanded RNA or dipeptides from non-ATG-initiated translation are responsible for the pathophysiology. We determined the interactome of C9ORF72 in motor neurons and found that C9ORF72 was present in a complex with cofilin and other actin binding proteins. Phosphorylation of cofilin was enhanced in C9ORF72-depleted motor neurons, in patient-derived lymphoblastoid cells, induced pluripotent stem cell-derived motor neurons and post-mortem brain samples from ALS patients. C9ORF72 modulates the activity of the small GTPases Arf6 and Rac1, resulting in enhanced activity of LIM-kinases 1 and 2 (LIMK1/2). This results in reduced axonal actin dynamics in C9ORF72-depleted motor neurons. Dominant negative Arf6 rescues this defect, suggesting that C9ORF72 acts as a modulator of small GTPases in a pathway that regulates axonal actin dynamics.
|Number of pages||9|
|Publication status||Published - Dec 2016|
- Actin Depolymerizing Factors, Actins, Amyotrophic Lateral Sclerosis, Animals, Brain, DNA Repeat Expansion, Frontotemporal Dementia, Guanine Nucleotide Exchange Factors, Humans, Induced Pluripotent Stem Cells, Mice, Microfilament Proteins, Motor Neurons, Proteins, Journal Article