HnRNP A1 contacts exon 5 to promote exon 6 inclusion of apoptotic Fas gene

Hyun Kyung Oh, Eunkyung Lee, Ha Na Jang, Jaehoon Lee, Heegyum Moon, Zhi Sheng, Youngsoo Jun, Tiing Jen Loh, Sunghee Cho, Jianhua Zhou, Michael R. Green, Xuexiu Zheng, Haihong Shen

Research output: Contribution to journalArticleResearchpeer-review

20 Citations (Scopus)

Abstract

Fas is a transmembrane cell surface protein recognized by Fas ligand (FasL). When FasL binds to Fas, the target cells undergo apoptosis. A soluble Fas molecule that lacks the transmembrane domain is produced from skipping of exon 6 encoding this region in alternative splicing procedure. The soluble Fas molecule has the opposite function of intact Fas molecule, protecting cells from apoptosis. Here we show that knockdown of hnRNP A1 promotes exon 6 skipping of Fas pre-mRNA, whereas overexpression of hnRNP A1 reduces exon 6 skipping. Based on the bioinformatics approach, we have hypothesized that hnRNP A1 functions through interrupting 5′ splice site selection of exon 5 by interacting with its potential binding site close to 5′ splice site of exon 5. Consistent with our hypothesis, we demonstrate that mutations of the hnRNP A1 binding site on exon 5 disrupted the effects of hnRNP A1 on exon 6 inclusion. RNA pull-down assay and then western blot analysis with hnRNP A1 antibody prove that hnRNP A1 contacts the potential binding site RNA sequence on exon 5 but not the mutant sequence. In addition, we show that the mutation of 5′ splice site on exon 5 to a less conserved sequence destructed the effects of hnRNP A1 on exon 6 inclusion. Therefore we conclude that hnRNP A1 interacts with exon 5 to promote distal exon 6 inclusion of Fas pre-mRNA. Our study reveals a novel alternative splicing mechanism of Fas pre-mRNA.

Original languageEnglish
Pages (from-to)825-835
Number of pages11
JournalApoptosis
Volume18
Issue number7
DOIs
Publication statusPublished - Jul 2013
Externally publishedYes

Keywords

  • 5′ splice site
  • Anti-apoptotic
  • Apoptotic
  • Exon 6
  • Fas
  • hnRNP A1
  • Pre-mRNA splicing

Cite this