title: Transcriptional repression by RING finger protein TIF1 beta that interacts with the KRAB repressor domain of KOX1.
abstract: Many of the vertebrate zinc finger factors of the Kruppel type (C2H2 zinc fingers) contain in their N-terminus a conserved sequence referred to as the KRAB (Kruppel-associated box) domain that, when tethered to DNA, efficiently represses transcription. Using the yeast two-hybrid system, we have isolated an 835 amino acid RING finger (C3HC4 zinc finger) protein, TIF1 beta (also named KAP-1), that specifically interacts with the KRAB domain of the human zinc finger factor KOX1/ZNF10. TIF1 beta, TIF1 alpha, PML and efp belong to a characteristic subgroup of RING finger proteins that contain one or two other Cys/His-rich clusters (B boxes) and a putative coiled-coil in addition to the classical C3HC4 RING finger motif (RBCC configuration). Like TIF1 alpha, TIF1 beta also contains an additional Cys/His cluster (PHD finger) and a bromo-related domain. When tethered to DNA, TIF1 beta can repress transcription in transiently transfected mammalian cells both from promoter-proximal and remote (enhancer) positions, similarly to the KRAB domain itself. We propose that TIF1 beta is a mediator of the transcriptional repression exerted by the KRAB domain.
authors.affiliation: Institut für Molekularbiologie der Universität, Abteilung II, Zürich, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Moosmann
authors.forename: O
authors.initials: O
authors.lastname: Georgiev
authors.forename: B
authors.initials: B
authors.lastname: Le Douarin
authors.forename: J P
authors.initials: JP
authors.lastname: Bourquin
authors.forename: W
authors.initials: W
authors.lastname: Schaffner
mesh_terms: D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D002888:Chromosomes, Human, Pair 19; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D000076183:Tripartite Motif-Containing Protein 28
chemical_list: D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; C101116:TRIM28 protein, human; D000076183:Tripartite Motif-Containing Protein 28