Transcriptional repression by RING finger protein TIF1 beta that interacts with the KRAB repressor domain of KOX1

Nucleic Acids Res. 1996 Dec 15;24(24):4859-67. doi: 10.1093/nar/24.24.4859.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Chromosome Mapping
  • Chromosomes, Human, Pair 19
  • Cloning, Molecular
  • DNA, Complementary
  • DNA-Binding Proteins / metabolism*
  • HeLa Cells
  • Humans
  • In Situ Hybridization, Fluorescence
  • Molecular Sequence Data
  • Recombinant Proteins / metabolism
  • Repressor Proteins / metabolism*
  • Sequence Homology, Amino Acid
  • Tripartite Motif-Containing Protein 28


  • DNA, Complementary
  • DNA-Binding Proteins
  • Recombinant Proteins
  • Repressor Proteins
  • TRIM28 protein, human
  • Tripartite Motif-Containing Protein 28

Associated data

  • GENBANK/X97548