HnRNP A1 Regulates Alternative Splicing of Tau Exon 10 by Targeting 3' Splice Sites.

Yongchao Liu,Xuexiu Zheng,Jianhua Zhou,Haihong Shen,Jiyeon Ha,Donggun Kim,Jagyeong Oh,Namjeong Choi

doi:10.3390/cells9040936

Yongchao Liu, Xuexiu Zheng + Show 6 more

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https://doi.org/10.3390/cells9040936

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Abstract

The ratio control of 4R-Tau/3R-Tau by alternative splicing of Tau exon 10 is important for maintaining brain functions. In this study, we show that hnRNP A1 knockdown induces inclusion of endogenous Tau exon 10, conversely, overexpression of hnRNP A1 promotes exon 10 skipping of Tau. In addition, hnRNP A1 inhibits splicing of intron 9, but not intron 10. Furthermore, hnRNP A1 directly interacts with the 3′ splice site of exon 10 to regulate its functions in alternative splicing. Finally, gene ontology analysis demonstrates that hnRNP A1-induced splicing and gene expression targets a subset of genes with neuronal function.

Highlights

Pre-mRNA splicing is a posttranscriptional process in which introns are removed from pre-mRNA and remaining exons are ligated to produce mRNA [1]
We showed that heterogenous nuclear ribonuclear proteins (hnRNPs) A1 knockdown induces inclusion of endogenous Tau exon
Tau exon 10 with lentivirus-mediated hnRNP A1-targeting shRNA treatment in SH-SY5Y cells, with human neuroblastoma cells, or as a control, non-silencing shRNA treatment followed by RT-PCR of

Summary

Introduction

Pre-mRNA splicing is a posttranscriptional process in which introns are removed from pre-mRNA and remaining exons are ligated to produce mRNA [1]. U1 snRNPs recognize 50 splice sites, U2 snRNPs recognize branch point sequences and U4/U5/U6 snRNPs form a catalytically active splicesome [1,4]. Pre-mRNA splicing occurs by two consecutive transesterification reactions: First, the hydroxyl group of adenosine in branch point attacks 50 end of intron to generate 50 exon and intron-30 exon RNA intermediate with a 20 –50 phosphordiester bond; second, 30 hydroxyl of the 50 exon attacks 30 splice site to result in ligation of the two exons and release of the introns in a lariat form [5,8]. Alternative splicing is a highly regulated process in eukaryotes by which a single gene may generate multiple proteins by differential inclusion of alternative exons in the mature mRNA sequences. RNA sequencing (RNA-seq) analysis in tissues has demonstrated that more than 90% of multiexon genes undergo alternative splicing to generate different mRNA isoforms [1,9,10]

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