SP100

This gene encodes a subnuclear organelle and major component of the PML (promyelocytic leukemia)-SP100 nuclear bodies. PML and SP100 are covalently modified by the SUMO-1 modifier, which is considered crucial to nuclear body interactions. The encoded protein binds heterochromatin proteins and is thought to play a role in tumorigenesis, immunity, and gene regulation. Alternatively spliced variants have been identified for this gene; one of which encodes a high-mobility group protein. [provided by RefSeq, Aug 2011]

SP100 Nuclear Antigen

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 PubMed:11909962. Under certain conditions, it may also act as a corepressor of ETS1 preventing its binding to DNA according to PubMed:15247905. 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.

Biological Process DNA damage response, signal transduction by p53 class mediator resulting in transcription of p21 class mediatorManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process interferon-gamma-mediated signaling pathway1 PublicationIC:BHF-UCL
Biological Process maintenance of protein locationManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process negative regulation of DNA bindingManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process negative regulation of DNA-binding transcription factor activityManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process negative regulation of DNA-templated transcriptionIDA:BHF-UCL
Biological Process negative regulation of endothelial cell migrationManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process negative regulation of protein export from nucleusManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process negative regulation of transcription by RNA polymerase IIManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process negative regulation of viral transcriptionIDA:BHF-UCL
Biological Process positive regulation of DNA-binding transcription factor activityIDA:BHF-UCL
Biological Process positive regulation of DNA-templated transcriptionManual Assertion Based On ExperimentIMP:BHF-UCL
Biological Process positive regulation of transcription by RNA polymerase IIIDA:BHF-UCL
Biological Process regulation of angiogenesisManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process regulation of extrinsic apoptotic signaling pathway via death domain receptorsManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process regulation of Fas signaling pathwayManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process regulation of transcription by RNA polymerase IIManual Assertion Based On ExperimentIBA:GO_Central
Biological Process response to cytokineIDA:BHF-UCL
Biological Process response to interferon-gammaManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process response to retinoic acidIDA:BHF-UCL
Biological Process response to type I interferonManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process retinoic acid receptor signaling pathwayIC:BHF-UCL
Biological Process telomere maintenanceManual Assertion Based On ExperimentIMP:UniProtKB
Biological Process type I interferon signaling pathway1 PublicationIC:BHF-UCL

Nucleus
Nucleus, PML body
Cytoplasm
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.
Isoform Sp100-C
Nucleus
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.

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.
(Microbial infection) Immediate early protein IE1 of human cytomegalovirus (HHV-5) interferes with the sumoylation of SP100.