Anti-Daxx Antibody Picoband®

DAXX (death-domain associated protein) also known as DAP6 (Death-associated protein 6) or BING2, was first discovered through its cytoplasmic interaction with the classical death receptor  Fas. Human  DAXX  encodes a 740-amino acid polypeptide containing a nuclear localization signal. Functional analyses by  Yang et al. (1997)   demonstrated that  Daxx  binds to the Fas death domain and enhances Fas-mediated apoptosis. The authors suggested that  DAXX  and FADD define 2 distinct apoptotic pathways downstream of Fas. The  DAXX  gene is mapped to human chromosome 6p21.3 by somatic cell hybrid panels and fluorescence in situ hybridization, a region containing the HLA and putative autoimmune disease genes. MSP58 overexpression relieved  DAXX-mediated transcriptional repression. Immunoprecipitation and Western blot analysis with  DAXX  mutants showed that the N terminus of  DAXX  interacts with the C terminus of DMAP. Transient expression of  DAXX  or DMAP1 caused repression of glucocorticoid receptor-mediated transcription.

Transcription corepressor known to repress transcriptional potential of several sumoylated transcription factors. Down-regulates basal and activated transcription. Its transcription repressor activity is modulated by recruiting it to subnuclear compartments like the nucleolus or PML/POD/ND10 nuclear bodies through interactions with MCSR1 and PML, respectively. Seems to regulate transcription in PML/POD/ND10 nuclear bodies together with PML and may influence TNFRSF6-dependent apoptosis thereby. Inhibits transcriptional activatiopn of PAX3 and ETS1 through protein-protein interactions. Modulates PAX5 activity; the function seems to involve CREBBP. Acts as an adapter protein in a MDM2-DAXX-USP7 complex by regulating the RING-finger E3 ligase MDM2 ubiquitination activity. Under non-stress condition, in association with the deubiquitinating USP7, prevents MDM2 self-ubiquitination and enhances the intrinsic E3 ligase activity of MDM2 towards TP53, thereby promoting TP53 ubiquitination and subsequent proteasomal degradation. Upon DNA damage, its association with MDM2 and USP7 is disrupted, resulting in increased MDM2 autoubiquitination and consequently, MDM2 degradation, which leads to TP53 stabilization. Acts as histone chaperone that facilitates deposition of histone H3.3. Acts as targeting component of the chromatin remodeling complex ATRX:DAXX which has ATP-dependent DNA translocase activity and catalyzes the replication-independent deposition of histone H3.3 in pericentric DNA repeats outside S-phase and telomeres, and the in vitro remodeling of H3.3-containing nucleosomes. Does not affect the ATPase activity of ATRX but alleviates its transcription repression activity. Upopn neuronal activation asociates with regulatory elements of selected immediate early genes where it promotes deposition of histone H3.3 which may be linked to transcriptional induction of these genes. Required for the recruitment of histone H3.3:H4 dimers to PML-nuclear bodies (PML- NBs) ; the process is independent of ATRX and facilitated by ASF1A; PML-NBs are suggested to function as regulatory sites for the incorporation of newly synthesized histone H3.3 into chromatin. In case of overexpression of centromeric histone variant CENPA (as found in various tumors) is involved in its mislocalization to chromosomes; the ectopic localization involves a heterotypic tetramer containing CENPA, and histones H3.3 and H4 and decreases binding of CTCF to chromatin. Proposed to mediate activation of the JNK pathway and apoptosis via MAP3K5 in response to signaling from TNFRSF6 and TGFBR2. Interaction with HSPB1/HSP27 may prevent interaction with TNFRSF6 and MAP3K5 and block DAXX-mediated apoptosis. In contrast, in lymphoid cells JNC activation and TNFRSF6-mediated apoptosis may not involve DAXX. Shows restriction activity towards human cytomegalovirus (HCMV) . .

1. Chang, H. Y., Nishitoh, H., Yang, X., Ichijo, H., Baltimore, D. Activation of apoptosis signal-regulating kinase 1 (ASK1) by the adapter protein Daxx. Science 281: 1860-1863, 1998. 2. Kiriakidou, M., Driscoll, D. A., Lopez-Guisa, J. M., Strauss, J. F., III. Cloning and expression of primate Daxx cDNAs and mapping of the human gene to chromosome 6p21.3 in the MHC region. DNA Cell Biol. 16: 1289-1298, 1997. 3. Yang, X., Khosravi-Far, R., Chang, H. Y., Baltimore, D. Daxx, a novel Fas-binding protein that activates JNK and apoptosis. Cell 89: 1067-1076, 1997.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.

Cytoplasm. Nucleus, nucleoplasm. Nucleus, PML body . Nucleus, nucleolus. Chromosome, centromere. Dispersed throughout the nucleoplasm, in PML/POD/ND10 nuclear bodies, and in nucleoli. Colocalizes with histone H3.3, ATRX, HIRA and ASF1A at PML-nuclear bodies. Colocalizes with a subset of interphase centromeres, but is absent from mitotic centromeres. Detected in cytoplasmic punctate structures. Translocates from the nucleus to the cytoplasm upon glucose deprivation or oxidative stress. Colocalizes with RASSF1 in the nucleus. Colocalizes with USP7 in nucleoplasma with accumulation in speckled structures.