Abstract
Here, we present evidence for a specific role of the splicing-related factor TCERG1 in regulating apoptosis in live cells by modulating the alternative splicing of the apoptotic genes Bcl-x and Fas. We show that TCERG1 modulates Bcl-x alternative splicing during apoptosis and its activity in Bcl-x alternative splicing correlates with the induction of apoptosis, as determined by assessing dead cells, sub-G1-phase cells, annexin-V binding, cell viability, and cleavage of caspase-3 and PARP-1. Furthermore, the effect of TCERG1 on apoptosis involved changes in mitochondrial membrane permeabilization. We also found that depletion of TCERG1 reduces the expression of the activated form of the pro-apoptotic mitochondrial membrane protein Bak, which remains inactive by heterodimerizing with Bcl-xL, preventing the initial step of cytochrome c release in Bak-mediated mitochondrial apoptosis. In addition, we provide evidence that TCERG1 also participates in the death receptor-mediated apoptosis pathway. Interestingly, TCERG1 also modulates Fas/CD95 alternative splicing. We propose that TCERG1 sensitizes a cell to apoptotic agents, thus promoting apoptosis by regulating the alternative splicing of both the Bcl-x and Fas/CD95 genes. Our findings may provide a new link between the control of alternative splicing and the molecular events leading to apoptosis.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Alternative Splicing / physiology*
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Apoptosis / physiology*
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Caspase 3 / genetics
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Caspase 3 / metabolism
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Cytochromes c / genetics
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Cytochromes c / metabolism
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HEK293 Cells
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HeLa Cells
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Humans
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Jurkat Cells
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Poly (ADP-Ribose) Polymerase-1
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Poly(ADP-ribose) Polymerases / genetics
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Poly(ADP-ribose) Polymerases / metabolism
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Transcriptional Elongation Factors / genetics
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Transcriptional Elongation Factors / metabolism*
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bcl-2 Homologous Antagonist-Killer Protein / genetics
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bcl-2 Homologous Antagonist-Killer Protein / metabolism
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bcl-X Protein / genetics
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bcl-X Protein / metabolism*
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fas Receptor / genetics
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fas Receptor / metabolism*
Substances
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BAK1 protein, human
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BCL2L1 protein, human
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FAS protein, human
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TCERG1 protein, human
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Transcriptional Elongation Factors
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bcl-2 Homologous Antagonist-Killer Protein
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bcl-X Protein
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fas Receptor
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Cytochromes c
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PARP1 protein, human
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Poly (ADP-Ribose) Polymerase-1
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Poly(ADP-ribose) Polymerases
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CASP3 protein, human
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Caspase 3
Grants and funding
This work was supported by grants from the Spanish Ministry of Economy and Competitiveness [grant numbers BFU2011-24577 and BFU2014-54660-R] and the Andalusian Government [Excellence Projects CVI-4626/2009 and BIO-2515/2012] to CS; the Spanish Ministry of Economy and Competitiveness [grant number BFU2013-44660-R] and the Andalusian Government [Excellence Project CTS-6587] to CHM; the Spanish Ministry of Economy and Competitiveness [grant numbers SAF2013-44677-R and FIS PI12/00506], the SPANISH AIDS Research Network RD12/0017/0015 that is included in Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2008-2011, Instituto de Salud Carlos III, European Region Development Fund, ERDF (FEDER) to MC and JA. MM was supported by a fellowship from the Spanish Ministry of Education (FPU program). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.