Attenuates Expression and Affects Alternative Splicing of a Subset of p53-Regulated Genes.

BACKGROUND

Loss of the p53-inducible in p53-proficient CRC cell lines results in increased sensitivity to DNA-damaging chemotherapeutics. Here, we comprehensively analyze how affects the p53-induced transcriptional program.

METHODS

Using a CRISPR/Cas9-approach, we deleted the p53 binding site in the promoter of SW480 colorectal cancer cells and subjected them to RNA-Seq analysis after the activation of ectopic p53. RNA affinity purification followed by mass spectrometry was used to identify proteins associated with .

RESULTS

Loss of the p53-inducibility of resulted in an ~1.8-fold increase in the number of significantly regulated mRNAs compared to wild-type cells after ectopic activation of p53. A subset of direct p53 target genes, such as and displayed significantly stronger induction when the p53-inducibility of was abrogated. Loss of the p53-inducibility of resulted in alternative splicing of a small number of mRNAs, such as , , and . Several RNA binding proteins involved in pre-mRNA splicing were identified as interaction partners of by mass spectrometry.

CONCLUSIONS

Our results suggest that may restrict the extent and strength of p53-mediated transcriptional changes via context-dependent regulation of the expression and splicing of a subset of p53-regulated genes.