PARP9 Antibody - #DF14015

ADP-ribosyltransferase which, in association with E3 ligase DTX3L, plays a role in DNA damage repair and in immune responses including interferon-mediated antiviral defenses. Within the complex, enhances DTX3L E3 ligase activity which is further enhanced by PARP9 binding to poly(ADP-ribose). In association with DTX3L and in presence of E1 and E2 enzymes, mediates NAD(+)-dependent mono-ADP-ribosylation of ubiquitin which prevents ubiquitin conjugation to substrates such as histones. During DNA repair, PARP1 recruits PARP9/BAL1-DTX3L complex to DNA damage sites via PARP9 binding to ribosylated PARP1. Subsequent PARP1-dependent PARP9/BAL1-DTX3L-mediated ubiquitination promotes the rapid and specific recruitment of 53BP1/TP53BP1, UIMC1/RAP80, and BRCA1 to DNA damage sites. In response to DNA damage, PARP9-DTX3L complex is required for efficient non-homologous end joining (NHEJ); the complex function is negatively modulated by PARP9 activity. Dispensable for B-cell receptor (BCR) assembly through V(D)J recombination and class switch recombination (CSR) (By similarity). In macrophages, positively regulates pro-inflammatory cytokines production in response to IFNG stimulation by suppressing PARP14-mediated STAT1 ADP-ribosylation and thus promoting STAT1 phosphorylation. Also suppresses PARP14-mediated STAT6 ADP-ribosylation.

ADP-ribosylated by PARP14.

Cytoplasm>Cytosol. Nucleus.
Note: Shuttles between the nucleus and the cytosol (PubMed:16809771). Translocates to the nucleus in response to IFNG or IFNB1 stimulation (PubMed:26479788). Export to the cytosol depends on the interaction with DTX3L (PubMed:16809771). Localizes at sites of DNA damage in a PARP1-dependent manner (PubMed:23230272, PubMed:28525742).

Expressed in lymphocyte-rich tissues, spleen, lymph nodes, peripheral blood lymphocytes and colonic mucosa. Expressed in macrophages. Also expressed in nonhematopoietic tissues such as heart and skeletal muscle. Isoform 2 is the predominant form. Most abundantly expressed in lymphomas with a brisk host inflammatory response. In diffuse large B-cell lymphomas tumors, expressed specifically by malignant B-cells.

Forms a stable complex with E3 ligase DTX3L; the interaction is required for PARP9 mediated ADP-ribosylation of ubiquitin. Interacts (via PARP catalytic domain) with DTX3L (via N-terminus). Forms a complex with STAT1 and DTX3L independently of IFNB1 or IFNG-mediated STAT1 'Tyr-701' phosphorylation. Forms a complex with STAT1, DTX3L and histone H2B HIST1H2BH/H2BJ; the interaction is likely to induce HIST1H2BH/H2BJ ubiquitination. Interacts (via N-terminus) with STAT1. Interacts with PARP14 in IFNG-stimulated macrophages; the interaction prevents PARP14-mediated STAT1 and STAT6 ADP-riboslylation. Interacts with PARP1 (when poly-ADP-ribosylated).

Macro domains 1 and 2 may be involved in the binding to poly(ADP-ribose) (PubMed:28525742, PubMed:26479788). Macro domain 2 is required for recruitment to DNA damage sites (PubMed:23230272). Macro domains 1 and 2 are probably dispensable for the interaction with STAT1 and DTX3L and for STAT1 phosphorylation (PubMed:26479788).