SP100 Human
Description
Chromatin Regulation and Transcriptional Control
SP100 isoforms interact with heterochromatin protein 1 (HP1) and PML to modulate chromatin structure:
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SP100A: Promotes chromatin decondensation, enhancing transcriptional activation of genes like ETS1 and p53 .
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SP100B/C/HMG: Bind unmethylated CpG DNA via their SAND domains, recruiting HP1 to repress transcription .
SUMOylation enhances SP100-HP1 complex stability, amplifying transcriptional repression .
Antiviral Immunity
SP100 restricts viral replication by:
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Limiting viral transcription: Inhibits human papillomavirus (HPV) and herpesvirus replication .
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Recruiting PML-NB components: Traps viral DNA in PML-NBs, blocking replication .
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Regulating interferon (IFN) pathways: IFN-α/γ upregulate SP100, enhancing antiviral responses .
Viral countermeasures: Herpesviruses (e.g., HCMV, EBV) and adenoviruses manipulate SP100 isoforms to evade host defenses .
Clinical Relevance in Cancer
SP100 expression correlates with malignancy in a context-dependent manner:
Dual role in cancer: SP100 acts as a tumor suppressor in gliomas but exhibits oncogenic potential in PAAD, likely due to isoform-specific effects .
Autoimmune and Infectious Disease Associations
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Primary Biliary Cirrhosis: SP100 autoantibodies are diagnostic markers, though their pathogenic role remains unclear .
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Viral Infections: SP100 restricts HPV, HCMV, and adenoviruses but is manipulated by viral proteins to evade host immunity .
Research Challenges and Future Directions
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Isoform-specific targeting: Developing therapies that selectively modulate SP100A (antitumor) vs. SP100B/C (pro-tumor) isoforms.
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Viral countermeasures: Investigating how herpesviruses degrade SP100C to evade PML-NB-mediated antiviral responses .
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Biomarker potential: SP100 expression levels in PAAD and gliomas warrant validation in larger cohorts for diagnostic utility .
Product Specs
Product Science Overview
SP100 is a nuclear antigen protein encoded by the SP100 gene. It is a significant component of the PML (promyelocytic leukemia)-SP100 nuclear bodies, which are subnuclear organelles involved in various physiological processes, including cell growth, differentiation, and apoptosis . The recombinant form of this protein, SP100 Recombinant Human, is often used in research to study its functions and interactions.
The SP100 gene is located on chromosome 2 and encodes a protein that is approximately 100 kDa in size . The protein consists of several domains, including a high-mobility group (HMG) domain, which is involved in DNA binding and chromatin organization . The recombinant version of SP100 is typically produced with a GST (glutathione S-transferase) tag at the N-terminal, which aids in its purification and detection .
SP100 plays multiple roles in cellular processes:
- Gene Regulation: SP100 functions as a transcriptional coactivator of ETS1 and ETS2, which are transcription factors involved in various cellular processes . It can also act as a corepressor under certain conditions, preventing ETS1 from binding to DNA .
- Tumor Suppression: Together with PML, SP100 is considered a tumor suppressor. It is involved in the regulation of cell growth and apoptosis, making it a crucial player in cancer biology .
- Immune Response: SP100 is implicated in the immune response, particularly in the context of viral infections. It interacts with viral proteins and may play a role in the cellular defense mechanisms against viruses like human cytomegalovirus and Epstein-Barr virus .
The recombinant SP100 protein is produced using an in vitro wheat germ expression system. This method ensures that the protein maintains its correct conformational folding, which is essential for its biological function . The protein is purified to a high degree, with a purity of over 80% as determined by SDS-PAGE and Coomassie blue staining .
SP100 Recombinant Human is used in various research applications:
