Transcriptional Repression by RING Finger Protein TIF1 That Interacts with the KRAB Repressor Domain of KOX1

作者：Peter Moosmann, Oleg Georgiev, Bertrand Le Douarin, Jean‐Pierre Bourquin, W. Schaffner · 发表于：Nucleic Acids Research · 年份：1996 · DOI：10.1093/nar/24.24.4859 · 被引用次数：289 · 研究领域：Genomics and Chromatin Dynamics、Plant Molecular Biology Research、RNA Research and Splicing

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.