Co-regulation of human PCNA and PCNA-AS1

Abstract

Proliferating cell nuclear antigen (PCNA) is a nuclear protein and has been known as a co-factor of DNA polymerase delta and a major component for DNA replication complex. A non-coding RNA gene named as PCNA-AS1 was identified with a length of 384 bp, overlapping with the first exon of human PCNA. PCNA-AS1 is transcribed in the opposite orientation to PCNA gene and its promoter is located in the first intron of PCNA. In this study, we confirmed the expression of PCNA-AS1 by RT-PCR and examine the effect of PCNA-AS1 knock-down on PCNA gene. Knocking down of PCNA-AS1 by siRNA showed a decrease in PCNA-AS1 gene expression as well as almost of PCNA expression. Knock down of PCNA has the same result by decreasing not only PCNA but also PCNA-AS1 gene expression. We solidified our results by western blot analysis using antibodies against PCNA. Finally, we suggest that two divergent promoters located in a close proximity arise more possibility for co-regulation and this event may occur via chromatin remodeling of chromosomal domains or the interaction of transcriptional complexes between adjacent sequences.