The p53 tumour suppressor regulates the transcription initiation of selected genes
by binding to specific DNA sequences at their promoters. Here we report a novel role
of p53 in transcription elongation in human cells. Our data demonstrate that upon
transcription elongation blockage, p53 is associated with genes that have not been
reported as its direct targets. p53 could be co-immunoprecipitated with active forms
of DNA-directed RNA polymerase II subunit 1 (RPB1), highlighting its association with
the elongating RNA polymerase II. During a normal transcription cycle, p53 and RPB1
are localised at distinct regions of selected non-canonical p53 target genes and this
pattern of localisation was changed upon blockage of transcription elongation. Additionally,
transcription elongation blockage induced the proteasomal degradation of RPB1. Our
results reveal a novel role of p53 in human cells during transcription elongation
blockage that may facilitate the removal of RNA polymerase II from DNA.
