title: Phosphorylation of SRSF1 is modulated by replicational stress.
abstract: DNA ligase I-deficient 46BR.1G1 cells show a delay in the maturation of replicative intermediates resulting in the accumulation of single- and double-stranded DNA breaks. As a consequence the ataxia telangiectasia mutated protein kinase (ATM) is constitutively phosphorylated at a basal level. Here, we use 46BR.1G1 cells as a model system to study the cell response to chronic replication-dependent DNA damage. Starting from a proteomic approach, we demonstrate that the phosphorylation level of factors controlling constitutive and alternative splicing is affected by the damage elicited by DNA ligase I deficiency. In particular, we show that SRSF1 is hyperphosphorylated in 46BR.1G1 cells compared to control fibroblasts. This hyperphosphorylation can be partially prevented by inhibiting ATM activity with caffeine. Notably, hyperphosphorylation of SRSF1 affects the subnuclear distribution of the protein and the alternative splicing pattern of target genes. We also unveil a modulation of SRSF1 phosphorylation after exposure of MRC-5V1 control fibroblasts to different exogenous sources of DNA damage. Altogether, our observations indicate that a relevant aspect of the cell response to DNA damage involves the post-translational regulation of splicing factor SRSF1 which is associated with a shift in the alternative splicing program of target genes to control cell survival or cell death.
authors: Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, 27100 Pavia, Italy.
authors: Valentina
authors: V
authors: Leva
authors: Serena
authors: S
authors: Giuliano
authors: Anna
authors: A
authors: Bardoni
authors: Serena
authors: S
authors: Camerini
authors: Marco
authors: M
authors: Crescenzi
authors: Antonella
authors: A
authors: Lisa
authors: Giuseppe
authors: G
authors: Biamonti
authors: Alessandra
authors: A
authors: Montecucco
mesh_terms: D017398:Alternative Splicing; D002461:Cell Line, Transformed; D004249:DNA Damage; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000235:genetics; D004261:DNA Replication; D006801:Humans; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D040901:Proteomics; D016601:RNA-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D000068103:Serine-Arginine Splicing Factors; D013312:Stress, Physiological / Q000235:genetics
chemical_list: C000607892:LIG1 protein, human; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D000068103:Serine-Arginine Splicing Factors; D011088:DNA Ligases; D000072481:DNA Ligase ATP