Locatelli, Denised'Errico, PaoloCapra, SilviaFinardi, AdeleColciaghi, FrancescaSetola, VeronicaTerao, MinekoGarattini, EnricoBattaglia, Giorgio2012-05-112012-05-112012-05-11201210.1111/j.1471-4159.2012.07689.xhttps://infoscience.epfl.ch/handle/20.500.14299/80245WOS:000302615700014The axonal survival of motor neuron (a-SMN) protein is a truncated isoform of SMN1, the spinal muscular atrophy (SMA) disease gene. a-SMN is selectively localized in axons and endowed with remarkable axonogenic properties. At present, the role of a-SMN in SMA is unknown. As a first step to verify a link between a-SMN and SMA, we investigated by means of over-expression experiments in neuroblastoma-spinal cord hybrid cell line (NSC34) whether SMA pathogenic mutations located in the N-terminal part of the protein affected a-SMN function. We demonstrated here that either SMN1 missense mutations or small intragenic re-arrangements located in the Tudor domain consistently altered the a-SMN capability of inducing axonal elongation in vitro. Mutated human a-SMN proteins determined in almost all NSC34 motor neurons the growth of short axons with prominent morphologic abnormalities. Our data indicate that the Tudor domain is critical in dictating a-SMN function possibly because it is an association domain for proteins involved in axon growth. They also indicate that Tudor domain mutations are functionally relevant not only for FL-SMN but also for a-SMN, raising the possibility that also a-SMN loss of function may contribute to the pathogenic steps leading to SMA.axon growthaxon swellingscytoskeletal abnormalitiesmotor neuronspinal muscular atrophyTudor domainDetermining Gene-ProductDisease Protein SmnMessenger-RnaTudor DomainGrowth ConesMouse ModelDefectsLocalizationDeletionsHudtext::journal::journal article::research article