TY  - JOUR
AU  - Zanella, Pietro
AU  - Loss, Isabel
AU  - Parlato, Rosanna
AU  - Weishaupt, Jochen H
AU  - Sala, Carlo
AU  - Verpelli, Chiara
AU  - Boeckers, Tobias M
AU  - Catanese, Alberto
TI  - ALS Mutations Shift the Isoelectric Point of the KIF5A C Terminal Inducing Protein Aggregation and TDP-43 Mislocalization.
JO  - The journal of neuroscience
VL  - 45
IS  - 31
SN  - 0270-6474
CY  - Washington, DC
PB  - Soc.
M1  - DZNE-2025-00928
SP  - e1658242025
PY  - 2025
AB  - Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by death of lower and upper motor neurons. Although the mechanism behind the selective neuron loss is still unclear, several heterogeneous genes have been causally linked to ALS. KIF5A encodes for a neuronally enriched kinesin involved in protein transport, and mutations within this gene have been causally linked to different motor neuron diseases. The mutations identified in ALS patients are mostly predicted to alter its mRNA splicing, leading to a frameshift mutation and an aberrant 39-aa-long sequence in the C-terminal domain of KIF5A. Here we found that ALS-related KIF5A mutations induce the accumulation of the mutant form of the protein in human motoneurons, which are also characterized by the cytosolic mislocalization of TDP-43. This ALS hallmark was even exacerbated upon overexpression of the ALS-KIF5A protein in cells differentiated from healthy controls and primary neurons, suggesting a pathological connection between the cellular load of the mutant protein and TDP-43 pathology. While the terminal domain of the WT isoform is characterized by an acid isoelectric point (pI), the ALS variant presents a basic pI due to the altered aminoacidic composition of this sequence. We thus generated a KIF5A-ALS isoform that retained part of the aberrant sequence but with lower pI. The overexpression of this mutated variant led to significantly lower protein aggregation and TDP-43 mislocalization than the ALS mutant. Our data show that re-establishing the correct pI rescues KIFA aggregation and significantly reduces the cytoplasmic mislocalization of TDP-43.
KW  - Kinesins: genetics
KW  - Kinesins: metabolism
KW  - Kinesins: chemistry
KW  - Humans
KW  - Amyotrophic Lateral Sclerosis: genetics
KW  - Amyotrophic Lateral Sclerosis: metabolism
KW  - Amyotrophic Lateral Sclerosis: pathology
KW  - DNA-Binding Proteins: metabolism
KW  - DNA-Binding Proteins: genetics
KW  - Mutation: genetics
KW  - Motor Neurons: metabolism
KW  - Animals
KW  - Protein Aggregation, Pathological: genetics
KW  - Protein Aggregation, Pathological: metabolism
KW  - Cells, Cultured
KW  - ALS (Other)
KW  - KIF5A (Other)
KW  - TDP-43 (Other)
KW  - aggregation (Other)
KW  - isoelectric point (Other)
KW  - Kinesins (NLM Chemicals)
KW  - KIF5A protein, human (NLM Chemicals)
KW  - DNA-Binding Proteins (NLM Chemicals)
KW  - TARDBP protein, human (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:40555518
C2  - pmc:PMC12311770
DO  - DOI:10.1523/JNEUROSCI.1658-24.2025
UR  - https://pub.dzne.de/record/280250
ER  -