Poly(ADP-Ribose) Polymerase 1 Promotes Transcriptional Repression of Integrated Retroviruses

p53 Expression Activation of HIV-1 Latency in U1 Cells

“…Poly (ADP-Ribose) Polymerase 1 (PARP-1) is an abundant nuclear enzyme that catalyzes the successive transfer of the ADP-ribose moiety of NAD + to a variety of nuclear proteins, including itself [23]. PARP-1 is required for the activation of NF-κB-dependent target genes, including HIV-1 LTR in reporter constructs and it may also play a role in HIV-1 integration [24].…”

Poly(ADP-ribose) polymerase-1 silences retroviruses independently of viral DNA integration or heterochromatin formation

“…One of these cellular models is the chicken B lymphoblastoid cell line DT40 that, within the PARP family, only expresses PARP-1 (Hochegger et al, 2006). These cells are a reliable model to study the role of PARP-1 in retroviruses, since it supports the early phase of the life cycle of gamma retrovirus-and lentivirusderived viral vectors (Barr et al, 2005;Beitzel & Bushman, 2003;Bueno et al, 2013;Mitta et al, 2004Mitta et al, , 2005Randow & Sale, 2006).…”

“…For example, the DNA damage sensor poly(ADP-ribose) polymerase-1 (PARP-1) (Ji & Tulin, 2010;Krishnakumar & Kraus, 2010) is recruited to the Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus genomes and impairs viral replication by modifying viral proteins involved in genome replication and partitioning (Ohsaki et al, 2004), whereas hepatitis B virus depends on PARP-1 for efficient transcription (Ko et al, 2013). In addition, PARP-1 represses the expression of retrotransposons in Drosophila (Kotova et al, 2010;2011;Tulin et al, 2002) and retroviruses in avian cells (Bueno et al, 2013).…”

“…Therefore, simpler organisms lacking this redundancy are advantageous to the study of PARP-1 (Bueno et al, 2013;Kotova et al, 2010;Pinnola et al, 2007;Tulin et al, 2002). One of these cellular models is the chicken B lymphoblastoid cell line DT40 that, within the PARP family, only expresses PARP-1 (Hochegger et al, 2006).…”

“…We took advantage of the DT40 cellular model to understand better the mechanism of action of PARP-1 in retroviral silencing (Bueno et al, 2013), by determining whether PARP-1-mediated silencing requires viral DNA integration. Since PARP-1 represses integrated retro-elements, it is possible that integration-induced DNA damage recruits PARP-1 to the invading genome causing transcriptional repression, as described for other types of DNA damage (Chou et al, 2010).…”