IFIBYNE   05513
INSTITUTO DE FISIOLOGIA, BIOLOGIA MOLECULAR Y NEUROCIENCIAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
UV-induced DNA lesions trigger an alternative splicing response mediated by the Nucleotide Excision Repair system, and the protein kinases ATR and GSK3b
Autor/es:
LUCIANA E. GIONO; GASTÓN SORIA; NICOLÁS NIETO MORENO; ADRIÁN CAMBINDO BOTTO; ALBERTO KORNBLIHTT; FLORENCIA VILLAFAÑEZ; MANUEL J. MUÑOZ
Lugar:
Nueva York
Reunión:
Congreso; Eukaryotic mRNA Processing; 2017
Institución organizadora:
Cold Spring Harbor Laboratory
Resumen:
DNA damage induced by UV light affects alternative splicing (AS) patterns genome-wide. Induction of DNA photolesions by UV irradiation is necessary and sufficient to trigger the AS response. This phenomenon is started by the repair process of photolesions through the nucleotide excision repair (NER) pathway, that induces a signaling cascade mediated by ATR which ends in the hyperphosphorylation of the carboxyl-terminal domain (CTD) of RNAPII. This in turn decreases transcriptional elongation, altering alternative splicing decisions in the context of the kinetic model of coupling between transcription and AS. We provided evidence that RNAPII is a target but not a sensor of DNA photolesions and that that NER factors and the protein kinase ATR are part of the cascade between DNA photolesions and RNAPII in epithelial cells (1). In order to identify other kinases involved in the pathway that regulates AS, we performed a screening with a Public Kinase Inhibitor Set of 686 compounds (PKIS2 library), provided by GlaxoSmithKline. We created a HeLa cell line stably transfected with an inducible AS fluorescent reporter eliciting either GFP or dsRed expression depending on whether an alternative exon is included or not. UV irradiation changed the alternative splicing pattern of the reporter both at the mRNA and protein levels, making it an appropriate system to perform this screening. Surprisingly, only 14 of the 700 inhibitors significantly inhibited the effect of UV irradiation on AS, being GSK3b (glycogen synthase kinase 3 beta) a common target of most of the identified inhibitors. A highly specific commercial inhibitor to GSK3b inhibited the UV effect on AS both of the reporter and of a set of endogenous AS events, thus confirming that GSK3b is part of the pathway in study. This is a novel function for GSK3b, which has been reported to act in regulation of gene expression but not linked to a UV-triggered DNA damage response.