PARP1

PARP1 poly(ADP-ribose)polymerase 1 is a multifunctional enzyme with a molecular weight of 116 kDa, consisting of three main structural domains: DNA binding domain, self-modification domain, and catalytic domain. PARP1 plays multiple important roles in cells, including DNA single-strand break repair, gene transcription regulation, and cell death regulation. When DNA is damaged, PARP1 is rapidly activated and recruits other repair proteins by forming a PARP-DNA complex to participate in DNA repair pathways such as base excision repair BER, non-homologous end joining NHEJ, and homologous recombination repair HRR. In addition, PARP1 changes chromatin structure and transcriptional activity through ADP ribosylation, interacts with transcription factors, and regulates gene expression. In severe DNA damage, the activation of PARP1 can also lead to NAD+ depletion and trigger cell death. The activity of PARP1 is regulated by tumor suppressor genes such as PTEN, and interacts with proteins such as ATM, BRCA1, and BRCA2 to participate in DNA damage response and cell cycle regulation. The development of PARP1 inhibitors has become an important strategy for treating specific types of cancer, especially in the treatment of ovarian cancer and breast cancer.