An assessment of poly (ADP-ribose) polymerase-1 role in normal and cancer cells

Poly (ADP-ribose) polymerase (PARP) is a superfamily of 18 proteins characterized by the PARP homology domain, the catalytic domain. This catalytic domain helps in the ADP-ribosylation of various acceptor proteins using nicotinamide adenine dinucleotide (NAD+) as a donor for ADP-ribose. PARP-1 and PARP-2 carry out 80% of poly-ADP-ribosylation of cellular protein. Hence, their combined knockout results in embryonic lethality of mice. PARP-1 consists of three major domains, namely, DNA binding domain, automodification domain, and a catalytic domain. These domains further consist of subdomains and motifs, which helps PARP-1 in a diverse function. PARP-1 is mainly involved in DNA damage detection and repair, but emerging evidence suggests its role in many other functions such as DNA synthesis, replication, apoptosis, necrosis, and cancer progression. Herein, we review the current state of the PARP-1 role in DNA damage repair and other biological processes including epithelial to mesenchymal transition (EMT). We have also observed the role of PARP-1 in modulating EMT regulators like E-cadherin, Vimentin, Claudin-1, Snail, Smad-4, Twist-1, and beta-catenin. Here, we have also attempted to relate the role of PARP-1 in EMT of cancer cells.