SMN1

Subcellular localization

Nuclear bodies, Cytosol

References: PMID:40924492

Functional category

• Metabolism
• Motile cilium & axoneme
• Signaling (Hedgehog
• GPCRs
• ion channels)

Function

Using a mouse model of severe SMA, we revealed an underlying neurodevelopmental phenotype in SMA where prenatal SMN-dependent defects in translation drove disruptions in nonmotile primary cilia across the central nervous system (CNS). Low levels of SMN caused widespread perturbations in translation at E14.5 targeting genes associated with primary cilia. The density of primary cilia in vivo, as well as cilial length in vitro, was significantly decreased in prenatal SMA mice. Proteomic analysis revealed downstream perturbations in primary cilia-regulated signaling pathways, including Wnt signaling. Cell proliferation was concomitantly reduced in the hippocampus of SMA mice. Prenatal transplacental therapeutic intervention with SMN-restoring risdiplam rescued primary cilia defects in SMA mouse embryos. Thus, SMN protein is required for normal cellular and molecular development of primary cilia in the CNS. Early, systemic treatment with SMN-restoring therapies can successfully target neurodevelopmental comorbidities in SMA(40924492).