XRCC1 – Strategies for coordinating and assembling a versatile DNA damage response

X-ray cross complementing protein 1 (XRCC1) is a DNA repair scaffold that supports base excision repair and single strand break repair, and is also a participant in other repair pathways. It also serves as an important co-transporter for several other repair proteins, including aprataxin and PNKP-like factor (APLF), and DNA Ligase 3α (LIG3). By combining highly specialized regions that help to organize specific repair functions with recruitment of additional enzymes whose contribution is dependent on the details of the damaged site, XRCC1 is able to handle an expanded range of problems that may arise as the repair progresses or in connection with other repair pathways with which it interfaces. This review discusses the interplay between these functions and considers some possible interactions that underlie its reported repair activities.