Anti-KAP1/TRIM28 Antibody Picoband®

Tripartite motif-containing 28 (TRIM28), also known as transcriptional intermediary factor 1β (TIF1β) and KAP1 (KRAB-associated protein-1), is a protein that in humans is encoded by the TRIM28 gene. The protein encoded by this gene mediates transcriptional control by interaction with the Kruppel-associated box repression domain found in many transcription factors. The protein localizes to the nucleus and is thought to associate with specific chromatin regions. KAP1 is a ubiquitously expressed protein involved in many critical functions including: transcriptional regulation, cellular differentiation and proliferation, DNA damage repair, viral suppression, and apoptosis. Its functionality is dependent upon post-translational modifications. Phosphorylation of KAP1 acts as a deactivator of the protein in many of its mechanisms while sumoylation acts as an activator.

Transcription intermediary factor 1-beta; TIF1-beta; E3 SUMO-protein ligase TRIM28;6.3.2.-; KRAB-associated protein 1; KAP-1; KRAB-interacting protein 1; KRIP-1; Nuclear corepressor KAP-1; RING finger protein 96; Tripartite motif-containing protein 28; TRIM28; KAP1, RNF96, TIF1B

E.coli-derived human KAP1 recombinant protein (Position: A699-P835) . Human KAP1 shares 94.9% amino acid (aa) sequence identity with both mouse and rat KAP1.

Apoptosis, Cancer, Cell Biology, Cell Death,2339, Chromatin Binding Proteins, Epigenetics and Nuclear Signaling, Invasion/Microenvironment, Proteasome / Ubiquitin, Proteolysis/Ubiquitin, Ring Finger E3 Ligase, Transcription, Transcription Factors, Ubiquitin E3 Enzymes

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. Also specifically sumoylates IRF7, thereby inhibiting its transactivation activity. Ubiquitinates p53/TP53 leading to its proteosomal degradation; the function is enhanced by MAGEC2 and MAGEA2, and possibly MAGEA3 and MAGEA6. Mediates the nuclear localization of KOX1, ZNF268 and ZNF300 transcription factors. In association with isoform 2 of ZFP90, is required for the transcriptional repressor activity of FOXP3 and the suppressive function of regulatory T-cells (Treg) (PubMed:23543754) . .

1. Capili AD, Schultz DC, RauscherIII FJ, Borden KL (Jan 2001) . Solution structure of the PHD domain from the KAP-1 corepressor: structural determinants for PHD, RING and LIM zinc-binding domains. The EMBO Journal 20 (1-2) : 165–77. 2. Iyengar, Sushma; Farnham, Peggy (2011-07-29) . KAP1 Protein: An Enigmatic Master Regulator of the Genome. The Journal of Biological Chemistry 286. 3. Reymond A, Meroni G, Fantozzi A, Merla G, Cairo S, Luzi L, Riganelli D, Zanaria E, Messali S, Cainarca S, Guffanti A, Minucci S, Pelicci PG, Ballabio A (May 2001) . The tripartite motif family identifies cell compartments. The EMBO Journal 20 (9) : 2140–51.

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.