Protein: TIF1B_RAT
Sequence: MAASAAAATAAASAATAASAASGSPGSGEGSAGGEKRPAASSAAAASASASSPAGGGGEAQELLEHCGVCRERLRPERDPRLLPCLHSACSACLGPATPAAANNSGDGGSAGDGAMVDCPVCKQQCYSKDIVENYFMRDSGSKASSDSQDANQCCTSCEDNAPATSYCVECSEPLCETCVEAHQRVKYTKDHTVRSTGPAKTRDGERTVYCNVHKHEPLVLFCESCDTLTCRDCQLNAHKDHQYQFLEDAVRNQRKLLASLVKRLGDKHATLQKNTKEVRSSIRQVSDVQKRVQVDVKMAILQIMKELNKRGRVLVNDAQKVTEGQQERLERQHWTMTKIQKHQEHILRFASWALESDNNTALLLSKKLIYFQLHRALKMIVDPVEPHGEMKFQWDLNAWTKSAEAFGKIVAERPGTNSTGPGPMAPPRAPGPLSKQGSGSSQPMEVQEGYGFGTDDPYSSAEPHVSGMKRSRSGEGEVSGLMRKVPRVSLERLDLDLTSDSQPPVFKVFPGSTTEDYNLIVIERGAAAAAAGQAGTVPPGAPGAPPLPGMAIVKEEETEAAIGAPPAAPEGPETKPVLMALTEGPGAEGPRLASPSGSTSSGLEVVAPEVTSAPVSGPGILDDSATICRVCQKPGDLVMCNQCEFCFHLDCHLPSLQDVPGEEWSCSLCHVLPDLKEEDGSLSLDGADSTGVVAKLSPANQRKCERVLLALFCHEPCRPLHQLATDSTFSMEQPGGTLDLTLIRARLQEKLSPPYSSPQEFAQDVGRMFKQFNKLTEDKADVQSIIGLQRFFETRMNDAFGDTKFSAVLVEPPPLNLPSAGLSSQELSGPGDGP
What is the function of this protein?
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 a 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).  Probably forms a corepressor complex required for activated KRAS-mediated promoter hypermethylation and transcriptional silencing of tumor suppressor genes (TSGs) or other tumor-related genes in colorectal cancer (CRC) cells.  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 genes with atypical chromatin signatures to establish or maintain/protect H3K9me3 at these transcriptionally active regions.
What are the official names of this protein?
Transcription intermediary factor 1-beta, TIF1-beta, E3 SUMO-protein ligase TRIM28, KRAB-associated protein 1, Nuclear corepressor KAP-1, RING-type E3 ubiquitin transferase TIF1-beta, Tripartite motif-containing protein 28.
What is the protein family that this protein belongs to?
Belongs to the TRIM/RBCC family.
What are the subcellular locations of this protein?
Nucleus. Note=Associated with centromeric heterochromatin during cell differentiation through CBX1.