Figure 3.

Schematic representation of p21 function during DNA repair. The example shown here is pertaining to NER, but it could be applied to other repair mechanisms where PCNA is involved. (A,B) The first step requiring PCNA in NER involves the incision of the fragment by XPF (stimulated by PCNA) and by XPG. The transition through this step could be favored by p21 enabling the release of XPG (and perhaps XPF) from PCNA for subsequent degradation (dotted line) to allow the next step of DNA pol δ-dependent DNA synthesis. (C,D) Similar to the previous step, p21, before being itself ubiquitinated and degraded, may be required to promote p12 subunit removal for degradation. Created with https://biorender.com/ (Toronto, ON, Canada) (accessed on 10 May 2022).