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Ribosome profiling of SMN-primed ribosomes and active ribosome profiling from brains of a mouse model of severe SMA

ABSTRACT: Spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality, with an incidence of around 1 in 6,000-10,000 live births. SMA is caused by low levels of full-length survival of motor neuron protein (SMN). We demonstrate that SMN binds to ribosomes and that this interaction is tissue-dependent. We performed ribosome profiling analyses on lysates from P5 wild-type mouse brains exposed to RNase I, from which we isolated SMN-primed ribosomes by immunoprecipitation. SMN-primed ribosomes are preferentially positioned within the first five codons of a set of mRNAs which are enriched for translational enhancer sequences in the 5’UTR and rare codons at the beginning of their coding sequence. These SMN-specific mRNAs are associated with neurogenesis, lipid metabolism, ubiquitination, chromatin regulation and translation. Additionally, we analyzed the positioning of active ribosomes using the Active-RiboSeq method based on RiboLace and compared early symptomatic SMA mouse brains to age-matched controls. We found that loss of SMN induces ribosome depletion, especially at the beginning of the coding sequence of SMN-specific mRNAs, leading to impairment of proteins involved in motor neuron function and stability. Keywords: motor neuron disease, spinal muscular atrophy, SMA, SMN, SMN1, survival of motor neuron, SMN-primed ribosome profiling, translation, RiboLace, Ribo-Seq, active translation, ribosome heterogeneity

ORGANISM(S): Mus musculus

PROVIDER: GSE154106 | GEO | 2020/08/11

REPOSITORIES: GEO

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