Abstract
The poly(ADP-ribose) polymerase (PARP) family consists of 17 members of nicotinamide adenine dinucleotide (NAD⁺)-dependent enzymes that regulate key biological processes by catalyzing adenosine diphosphate (ADP)-ribosylation, either poly(ADP-ribosyl)ation (PARylation) or mono(ADP-ribosyl)ation (MARylation). These biological processes encompass DNA repair, metabolism, telomere maintenance, and immune responses. Based on structural and functional features, the PARP family is classified into subcategories, such as DNA-dependent PARPs, Tankyrase, CCCH-type PARPs, MacroPARPs, and atypical PARPs. These enzymes dynamically maintain genome stability through mechanisms, including base excision repair and homologous recombination, while also regulating telomere dynamics and metabolic pathways. Dysregulation of PARP activity is implicated in the pathogenesis of diverse human diseases. Though PARP inhibitors have gained therapeutic interest in oncology, their wider roles in nononcological conditions, such as neurodegenerative diseases, cardiovascular disorders, and viral infections, remain poorly defined. This review elucidates the unique structural features of PARP family members and describes their multiple roles under physiological and pathological conditions, thus providing insights into treatment strategies. Additionally, it summarizes the advances and challenges in PARP-targeted therapies and explores future directions for innovative therapeutic approaches. The findings may serve as a valuable resource for informing both clinical research and drug development.