Our Abpromise guarantee covers the use of ab3831 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
ChIP Use at an assay dependent concentration.
ICC/IF Use a concentration of 5 µg/ml.
IHC-P Use a concentration of 4 - 6 µg/ml. Perform heat mediated antigen retrieval with citrate buffer pH 6 before commencing with IHC staining protocol.
CHIPseq Use at an assay dependent concentration. PubMed: 21170338
IHC-Fr Use at an assay dependent concentration. PubMed: 16880268
WB Use a concentration of 1 - 3 µg/ml. Detects a band of approximately 110 kDa (predicted molecular weight: 100 kDa).
IP Use at an assay dependent concentration. PubMed: 16880268


  • Function

    Nuclear corepressor for KRAB domain-containing zinc finger proteins (KRAB-ZFPs). Mediates gene silencing by recruiting CHD3, a subunit of the nucleosome remodeling and deacetylation (NuRD) complex, and SETDB1 (which specifically methylates histone H3 at 'Lys-9' (H3K9me)) to the promoter regions of KRAB target genes. Enhances transcriptional repression by coordinating the increase in H3K9me, the decrease in histone H3 'Lys-9 and 'Lys-14' acetylation (H3K9ac and H3K14ac, respectively) and the disposition of HP1 proteins to silence gene expression. Recruitment of SETDB1 induces heterochromatinization. May play a role as a coactivator for CEBPB and NR3C1 in the transcriptional activation of ORM1. Also corepressor for ERBB4. Inhibits E2F1 activity by stimulating E2F1-HDAC1 complex formation and inhibiting E2F1 acetylation. May serve as a partial backup to prevent E2F1-mediated apoptosis in the absence of RB1. Important regulator of CDKN1A/p21(CIP1). Has E3 SUMO-protein ligase activity toward itself via its PHD-type zinc finger.
  • Tissue specificity

    Expressed in all tissues tested including spleen, thymus, prostate, testis, ovary, small intestine, colon and peripheral blood leukocytes.
  • Pathway

    Protein modification; protein sumoylation.
  • Sequence similarities

    Belongs to the TRIM/RBCC family.
    Contains 2 B box-type zinc fingers.
    Contains 1 bromo domain.
    Contains 1 PHD-type zinc finger.
    Contains 1 RING-type zinc finger.
  • Domain

    The HP1 box is both necessary and sufficient for HP1 binding.
    The PHD-type zinc finger enhances CEBPB transcriptional activity. The PHD-type zinc finger, the HP1 box and the bromo domain, function together to assemble the machinery required for repression of KRAB domain-containing proteins. Acts as an intramolecular SUMO E3 ligase for autosumoylation of bromodomain.
    The RING-finger-B Box-coiled-coil/tripartite motif (RBCC/TRIM motif) is required for interaction with the KRAB domain of KRAB-zinc finger proteins. Binds four zinc ions per molecule. The RING finger and the N-terminal of the leucine zipper alpha helical coiled-coil region of RBCC are required for oligomerization.
    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.
  • Post-translational

    Phosphorylated upon DNA damage, probably by ATM or ATR. ATM-induced phosphorylation on Ser-824 represses sumoylation leading to the de-repression of expression of a subset of genes involved in cell cycle control and apoptosis in response to genotoxic stress. Dephosphorylation by the phosphatases, PPP1CA and PP1CB forms, allows sumoylation and expression of TRIM28 target genes.
    Sumoylation/desumoylation events regulate TRIM28-mediated transcriptional repression. Sumoylation is required for interaction with CHD3 and SETDB1 and the corepressor activity. Represses and is repressed by Ser-824 phosphorylation. Enhances the TRIM28 corepressor activity, inhibiting transcriptional activity of a number of genes including GADD45A and CDKN1A/p21. Lys-554, Lys-779 and Lys-804 are the major sites of sumoylation. In response to Dox-induced DNA damage, enhanced phosphorylation on Ser-824 prevents sumoylation and allows de-repression of CDKN1A/p21.
  • Cellular localization

    Nucleus. Associated with centromeric heterochromatin during cell differentiation through CBX1.
  • Information by UniProt
  • Database links

  • Alternative names

    • E3 SUMO protein ligase TRIM28 antibody
    • E3 SUMO-protein ligase TRIM28 antibody
    • FLJ29029 antibody
    • KAP 1 antibody
    • KAP-1 antibody
    • KRAB associated protein 1 antibody
    • KRAB interacting protein 1 antibody
    • KRAB-associated protein 1 antibody
    • KRAB-interacting protein 1 antibody
    • KRIP 1 antibody
    • KRIP-1 antibody
    • KRIP1 antibody
    • Nuclear corepressor KAP 1 antibody
    • Nuclear corepressor KAP-1 antibody
    • RING finger protein 96 antibody
    • RNF96 antibody
    • TF1B antibody
    • TIF1 beta antibody
    • TIF1-beta antibody
    • TIF1B antibody
    • TIF1B_HUMAN antibody
    • Transcription intermediary factor 1 beta antibody
    • Transcription intermediary factor 1-beta antibody
    • Trim28 antibody
    • Tripartite motif containing 28 antibody
    • tripartite motif containing protein 28 antibody
    • Tripartite motif-containing protein 28 antibody
    see all


  • ab3831 staining (0.5µg/ml) of HepG2 lysate (RIPA buffer, 30µg total protein per lane).  Primary incubated for 1 hour.  Detected by western blot using chemiluminescence. ab3831 staining (0.5µg/ml) of HepG2 lysate (RIPA buffer, 30µg total protein per lane). Primary incubated for 1 hour. Detected by western blot using chemiluminescence.
  • TIF1b is uniformly distributed in the two pronuclei of the mouse embryo at the late zygote stage. Mouse zygotes were processed for immunostaining using the KAP1 antibody. DNA is shown in blue. The dilution used was 1 to 100 in PBS-Tween with 3% BSA. This is part of the review submitted by ME Torres-Padilla on 27 July 2004.
  • ab3831 at 2.5 µg/ml staining KAP1 in Human breast tissue by Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections). Steamed antigen retrieval with citrate buffer pH 6, AP-staining.
  • ab3831 (4µg/ml) staining of paraffin embedded Human Breast shows nuclear staining in epithelial duct cells. Steamed antigen retrieval with citrate buffer pH 6, HRP-staining.


This product has been referenced in:

  • Himeda CL  et al. CRISPR/dCas9-mediated Transcriptional Inhibition Ameliorates the Epigenetic Dysregulation at D4Z4 and Represses DUX4-fl in FSH Muscular Dystrophy. Mol Ther 24:527-35 (2016). ChIP ; Human . Read more (PubMed: 26527377) »
  • Nakajima NI  et al. Pre-exposure to ionizing radiation stimulates DNA double strand break end resection, promoting the use of homologous recombination repair. PLoS One 10:e0122582 (2015). WB . Read more (PubMed: 25826455) »
See all 7 Publications for this product

Customer reviews and Q&As

1-8 of 8 Abreviews or Q&A

Western blot
Mouse Cell lysate - whole cell (MEF)
Gel Running Conditions
Reduced Denaturing (4-20%)
Loading amount
10 µg
Blocking step
Milk as blocking agent for 30 minute(s) · Concentration: 5% · Temperature: 25°C

Abcam user community

Verified customer

Submitted Apr 24 2019

Immunocytochemistry/ Immunofluorescence
Human Cell (HeLa)
Yes - 0.5% Triton 5 minutes
Blocking step
Serum as blocking agent for 30 minute(s) · Concentration: 5% · Temperature: RT°C

Abcam user community

Verified customer

Submitted Oct 26 2017

Western blot
Human Cell lysate - whole cell (HEK293)
Gel Running Conditions
Reduced Denaturing
Loading amount
10 µg
1uM CPT 1hr
Blocking step
Milk as blocking agent for 30 minute(s) · Concentration: 5% · Temperature: 25°C

Abcam user community

Verified customer

Submitted Jul 05 2016

Human Cell lysate - nuclear (K562 cells)
K562 cells
Cross-linking (X-ChIP)
Duration of cross-linking step: 10 minute(s) and 0 second(s)
Specification of the cross-linking agent: formaldehyde
Detection step

Dr. Seth Frietze

Verified customer

Submitted Mar 08 2011


Thank you for your email. This antibody was originally characterized for application in Western blotting using human samples (HepG2 whole cell lysate). We received feedback from a customer who successfully used ab3831 with mouse samples (mouse embryos) in Western blotting and IF. You may read this review by clicking on the reviews tab located on the online datasheet. You may also send an email to the reviewer by clicking on the name. As I previously mentioned, I would suggest using HepG2 whole cell lysate as a positive control. On the online datasheet for ab3831, there is also a nice Western blot image showing the results with this lysate. Please let me know if you need further assistance.

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Thank you for your email and I'm sorry to hear that your customer is experiencing difficulty with ab3831. At this point I would like to make some suggestions to try to assist your customer. To decrease the background, try blocking with BSA rather than milk. I also suggest decreasing the concentrations of both the primary and secondary antibodies and decrease the incubation periods. In addition, increase the number of washes. I also strongly suggest running a positive control. Ab3831 was characterized using HepG2 whole cell lysate, which is recommended as positive control. If these suggestions do not help, please let me know.

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Thank you for your enquiry. According to Swiss Prot and Ugene the predicted molecular weight of this target should be approximately 100 kDa. We have updated the relevant public facing site in order to reflect this data. However, we would like to emphasize that this antibody has been tested and characterized on HepG2 (human hepatocellular cancer cell line). According to Swiss-Prot database, there are alternative splice variants and isoforms which may cause shift in the band size. We would like to thank you for bringing this matter to our attention.

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By BLAST analysis I can find no significant similarity between the epitope used to generate this antibody (Peptide with sequence SSQELSGGPGDGP, from C Terminus of the protein sequence according) and any epitopes in TIF 1 alpha. I therfore think it is highly unlikely that the antibody cross reacts with TIF 1 alpha.

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