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标题：The Clp1 R140H mutation alters tRNA metabolism and mRNA 3′ processing in mouse models of pontocerebellar hypoplasia
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作者：Caitlin E. Monaghan ; Scott I. Adamson ; Mridu Kapur 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2021
卷号：118
期号：39
DOI：10.1073/pnas.2110730118
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Significance Mutation of CLP1 causes pontocerebellar hypoplasia type 10 (PCH10), a neurodegenerative disorder associated with intellectual and motor disability. We made two mouse models of PCH10: one homozygous for the mutation found in patients and one heterozygous for this mutation and a null allele. Mutant mice had motor impairments and neurodegeneration in the spinal cord and cerebellum. Mutants also had altered tRNA metabolism; however, it is not clear whether these alterations contribute to pathogenesis. In addition, mutation of Clp1 resulted in altered poly(A) site selection and gene expression, suggesting that the role of CLP1 in mRNA 3′ end processing could be a promising avenue for future research into the pathogenesis of PCH10. Homozygous mutation of the RNA kinase CLP1 (cleavage factor polyribonucleotide kinase subunit 1) causes pontocerebellar hypoplasia type 10 (PCH10), a pediatric neurodegenerative disease. CLP1 is associated with the transfer RNA (tRNA) splicing endonuclease complex and the cleavage and polyadenylation machinery, but its function remains unclear. We generated two mouse models of PCH10: one homozygous for the disease-associated Clp1 mutation, R140H, and one heterozygous for this mutation and a null allele. Both models exhibit loss of lower motor neurons and neurons of the deep cerebellar nuclei. To explore whether Clp1 mutation impacts tRNA splicing, we profiled the products of intron-containing tRNA genes. While mature tRNAs were expressed at normal levels in mutant mice, numerous other products of intron-containing tRNA genes were dysregulated, with pre-tRNAs, introns, and certain tRNA fragments up-regulated, and other fragments down-regulated. However, the spatiotemporal patterns of dysregulation do not correlate with pathogenicity for most altered tRNA products. To elucidate the effect of Clp1 mutation on precursor messenger RNA (pre-mRNA) cleavage, we analyzed poly(A) site (PAS) usage and gene expression in Clp1 R140H/− spinal cord. PAS usage was shifted from proximal to distal sites in the mutant mouse, particularly in short and closely spaced genes. Many such genes were also expressed at lower levels in the Clp1 R140H/− mouse, possibly as a result of impaired transcript maturation. These findings are consistent with the hypothesis that select genes are particularly dependent upon CLP1 for proper pre-mRNA cleavage, suggesting that impaired mRNA 3′ processing may contribute to pathogenesis in PCH10.
关键词：enmotor neuron degeneration;tRNA splicing;cleavage factor II;deep cerebellar nuclei;alternative polyadenylation