Genome-wide identification of Fas/CD95 alternative splicing regulators reveals links with iron homeostasis

J Ramón Tejedor; Panagiotis Papasaikas; Juan Valcárcel

doi:10.1016/j.molcel.2014.10.029

Genome-wide identification of Fas/CD95 alternative splicing regulators reveals links with iron homeostasis

Mol Cell. 2015 Jan 8;57(1):23-38. doi: 10.1016/j.molcel.2014.10.029. Epub 2014 Dec 4.

Authors

J Ramón Tejedor¹, Panagiotis Papasaikas¹, Juan Valcárcel²

Affiliations

¹ Centre de Regulació Genòmica, Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra, Dr. Aiguader 88, 08003 Barcelona, Spain.
² Centre de Regulació Genòmica, Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra, Dr. Aiguader 88, 08003 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats, Pg Lluis Companys, 23, 08003 Barcelona, Spain. Electronic address: juan.valcarcel@crg.eu.

PMID: 25482508
DOI: 10.1016/j.molcel.2014.10.029

Abstract

Alternative splicing of Fas/CD95 exon 6 generates either a membrane-bound receptor that promotes, or a soluble isoform that inhibits, apoptosis. Using an automatized genome-wide siRNA screening for alternative splicing regulators of endogenous transcripts in mammalian cells, we identified 200 genes whose knockdown modulates the ratio between Fas/CD95 isoforms. These include classical splicing regulators; core spliceosome components; and factors implicated in transcription and chromatin remodeling, RNA transport, intracellular signaling, and metabolic control. Coherent effects of genes involved in iron homeostasis and pharmacological modulation of iron levels revealed a link between intracellular iron and Fas/CD95 exon 6 inclusion. A splicing regulatory network linked iron levels with reduced activity of the Zinc-finger-containing splicing regulator SRSF7, and in vivo and in vitro assays revealed that iron inhibits SRSF7 RNA binding. Our results uncover numerous links between cellular pathways and RNA processing and a mechanism by which iron homeostasis can influence alternative splicing.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alternative Splicing*
Apoptosis / drug effects
Apoptosis Regulatory Proteins
Binding Sites
Cell Proliferation / drug effects
Deferoxamine / pharmacology
Exons
Gene Regulatory Networks*
Genome*
Genome-Wide Association Study
HeLa Cells
Homeostasis
Humans
Intracellular Signaling Peptides and Proteins / genetics
Intracellular Signaling Peptides and Proteins / metabolism
Introns
Iron / metabolism*
Iron / pharmacology
Iron Chelating Agents / pharmacology
Mitochondrial Proteins / genetics
Mitochondrial Proteins / metabolism
Molecular Sequence Annotation
Nuclear Proteins / genetics
Nuclear Proteins / metabolism
Protein Binding
Protein Isoforms / antagonists & inhibitors
Protein Isoforms / genetics
Protein Isoforms / metabolism
RNA, Small Interfering / genetics
RNA, Small Interfering / metabolism
RNA-Binding Proteins / genetics
RNA-Binding Proteins / metabolism
Serine-Arginine Splicing Factors
Spliceosomes / chemistry
Spliceosomes / drug effects
Spliceosomes / metabolism*
fas Receptor / antagonists & inhibitors
fas Receptor / genetics*
fas Receptor / metabolism

Substances

Apoptosis Regulatory Proteins
DIABLO protein, human
Intracellular Signaling Peptides and Proteins
Iron Chelating Agents
Mitochondrial Proteins
Nuclear Proteins
Protein Isoforms
RNA, Small Interfering
RNA-Binding Proteins
fas Receptor
Serine-Arginine Splicing Factors
Iron
Deferoxamine

Associated data

SRA/SRP050031