TIF1B
a member of the transcriptional intermediary factor 1 (TIF1) family of proteins that play key roles in development and differentiation. Members of this family are characterized by the presence of an N-terminal B-box-type zinc finger domain and a C-terminal PHD domain and bromodomain. Mediates transcriptional regulation by interaction with the Kruppel-associated box (KRAB) repression domain found in many transcription factors. Binds to the negative regulatory domain of c-Myb and negatively regulates the c-Myb-dependent trans-activation. Localizes to the nucleus and is thought to associate with specific chromatin regions. Phosphorylated in an ATM-dependent manner following double-strand breaks. Its phosphorylation in response to DNA damage leads to chromatin relaxation. A member of the tripartite motif family. The tripartite motif includes three zinc-binding domains, a RING, a B-box type 1 and a B-box type 2, and a coiled-coil region. Note: This description may include information from UniProtKB. 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. Is a corepressor for ERBB4. Inhibits E2F1 activity by stimulating E2F1-HDAC1 complex formation and inhibiting E2F1 acetylation. Is an important regulator of p21Cip1. 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). Required to maintain a transcriptionally repressive state of genes in undifferentiated embryonic stem cells (ESCs). In ESCs, in collaboration with SETDB1, is also required for H3K9me3 and silencing of endogenous and introduced retroviruses in a DNA-methylation independent-pathway. Associates at promoter regions of tumor suppressor genes (TSGs) leading to their gene silencing. The SETDB1-TRIM28-ZNF274 complex may play a role in recruiting ATRX to the 3'-exons of zinc-finger coding genes with atypical chromatin signatures to establish or maintain/protect H3K9me3 at these transcriptionally active regions. Acts as a corepressor for ZFP568. Belongs to the TRIM/RBCC family. Expressed in all tissues tested including spleen, thymus, prostate, testis, ovary, small intestine, colon and peripheral blood leukocytes. 2 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Molecular Function: chromatin binding; chromo shadow domain binding; DNA binding; Krueppel-associated box domain binding; metal ion binding; promoter-specific chromatin binding; protein binding; protein kinase activity; SUMO transferase activity; transcription coactivator activity; transcription corepressor activity; transferase activity; ubiquitin protein ligase activity; ubiquitin protein ligase binding; ubiquitin-protein transferase activity; zinc ion binding
Biological Process: chromatin organization; convergent extension involved in axis elongation; DNA repair; embryo implantation; embryonic placenta morphogenesis; epithelial to mesenchymal transition; in utero embryonic development; innate immune response; negative regulation of DNA demethylation; negative regulation of DNA-templated transcription; negative regulation of single stranded viral RNA replication via double stranded DNA intermediate; negative regulation of transcription by RNA polymerase II; positive regulation of DNA binding; positive regulation of DNA methylation-dependent heterochromatin formation; positive regulation of DNA repair; positive regulation of DNA-templated transcription; positive regulation of protein binding; positive regulation of protein import into nucleus; post-fertilization epigenetic regulation of gene expression; protein autophosphorylation; protein phosphorylation; protein sumoylation; suppression of viral release by host
