SP100 Antibody - #DF4247

Together with PML, this tumor suppressor is a major constituent of the PML bodies, a subnuclear organelle involved in a large number of physiological processes including cell growth, differentiation and apoptosis. Functions as a transcriptional coactivator of ETS1 and ETS2 according to. Under certain conditions, it may also act as a corepressor of ETS1 preventing its binding to DNA according to. Through the regulation of ETS1 it may play a role in angiogenesis, controlling endothelial cell motility and invasion. Through interaction with the MRN complex it may be involved in the regulation of telomeres lengthening. May also regulate TP53-mediated transcription and through CASP8AP2, regulate FAS-mediated apoptosis. Also plays a role in infection by viruses, including human cytomegalovirus and Epstein-Barr virus, through mechanisms that may involve chromatin and/or transcriptional regulation.

Sumoylated. Sumoylation depends on a functional nuclear localization signal but is not necessary for nuclear import or nuclear body targeting.

Sumoylated. Sumoylated with SUMO1. Sumoylation depends on a functional nuclear localization signal but is not necessary for nuclear import or nuclear body targeting. Sumoylation may stabilize the interaction with CBX5.

Nucleus. Nucleus>PML body. Cytoplasm.
Note: Differences in the subnuclear localization of the different isoforms seem to exist and may also be cell cycle- and interferon-dependent. Accumulates in the cytoplasm upon FAS activation.

Nucleus.
Note: Forms a reticulate or track-like nuclear pattern with denser concentrations at the nuclear lamina and surrounding the nucleoli, a pattern reminiscent of heterochromatin-rich regions according to PubMed:11313457.

Widely expressed. Sp100-B is expressed only in spleen, tonsil, thymus, mature B-cell line and some T-cell line, but not in brain, liver, muscle or non-lymphoid cell lines.

Homodimer; isoforms are able to heterodimerize. Interacts with members of the HP1 family of nonhistone chromosomal protein, such as CBX5 and CBX3 via the PxVxL motif. Interacts with ETS1; the interaction is direct and modulates ETS1 transcriptional activity. Interacts with the MRN complex which is composed of two heterodimers RAD50/MRE11 associated with a single NBN; recruits the complex to PML-related bodies. Interacts with HIPK2; positively regulates TP53-dependent transcription. Interacts with CASP8AP2; may negatively regulate CASP8AP2 export from the nucleus to the cytoplasm. Interacts with SUMO1P1/SUMO5.

(Microbial infection) Interacts with Epstein-Barr virus EBNA-LP; this interaction is important for EBNA-LP coactivator activity.

(Microbial infection) Interacts with human cytomegalovirus/HHV-5 protein UL123; may play a role in infection by the virus.

The HSR domain is important for the nuclear body targeting as well as for the dimerization.

Contains one Pro-Xaa-Val-Xaa-Leu (PxVxL) motif, which is required for interaction with chromoshadow domains. This motif requires additional residues -7, -6, +4 and +5 of the central Val which contact the chromoshadow domain.