MicroRNA-mediated gene silencing modulates the UV-induced DNA-damage response.
DNA damage provokes DNA repair, cell-cycle regulation and apoptosis. This DNA-damage response encompasses gene-expression regulation at the transcriptional and post-translational levels. We show that cellular responses to UV-induced DNA damage are also regulated at the post-transcriptional level by microRNAs. Survival and checkpoint response after UV damage was severely reduced on microRNA-mediated gene-silencing inhibition by knocking down essential components of the microRNA-processing pathway (Dicer and Ago2). UV damage triggered a cell-cycle-dependent relocalization of Ago2 into stress granules and various microRNA-expression changes. Ago2 relocalization required CDK activity, but was independent of ATM/ATR checkpoint signalling, whereas UV-responsive microRNA expression was only partially ATM/ATR independent. Both microRNA-expression changes and stress-granule formation were most pronounced within the first hours after genotoxic stress, suggesting that microRNA-mediated gene regulation operates earlier than most transcriptional responses. The functionality of the microRNA response is illustrated by the UV-inducible miR-16 that downregulates checkpoint-gene CDC25a and regulates cell proliferation. We conclude that microRNA-mediated gene regulation adds a new dimension to the DNA-damage response.
Pothof
Joris
J
Department of Cell Biology and Genetics, Erasmus MC, CA Rotterdam 3000, The Netherlands.
Verkaik
Nicole S
NS
van IJcken
Wilfred
W
Wiemer
Erik A C
EA
Ta
Van T B
VT
van der Horst
Gijsbertus T J
GT
Jaspers
Nicolaas G J
NG
van Gent
Dik C
DC
Hoeijmakers
Jan H J
JH
Persengiev
Stephan P
SP
D060565:Argonaute Proteins; D049109:Cell Proliferation; D002478:Cells, Cultured; D003594:Cytoplasmic Granules; D004260:DNA Repair; D015852:Eukaryotic Initiation Factor-2 / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology; D016193:G1 Phase; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism; D016196:S Phase; D014466:Ultraviolet Rays
C466422:AGO2 protein, human; D060565:Argonaute Proteins; D015852:Eukaryotic Initiation Factor-2; C505362:MIRN16 microRNA, human; D035683:MicroRNAs; D043244:Ribonuclease III