TIF1gamma, a novel member of the transcriptional intermediary factor 1 family

Oncogene. 1999 Feb 4;18(5):1209-17. doi: 10.1038/sj.onc.1202655.

Abstract

We report the cloning and characterization of a novel member of the Transcriptional Intermediary Factor 1 (TIF1) gene family, human TIF1gamma. Similar to TIF1alpha and TIF1beta, the structure of TIF1beta is characterized by multiple domains: RING finger, B boxes, Coiled coil, PHD/TTC, and bromodomain. Although structurally related to TIF1alpha and TIF1beta, TIF1gamma presents several functional differences. In contrast to TIF1alpha, but like TIF1beta, TIF1 does not interact with nuclear receptors in yeast two-hybrid or GST pull-down assays and does not interfere with retinoic acid response in transfected mammalian cells. Whereas TIF1alpha and TIF1beta were previously found to interact with the KRAB silencing domain of KOX1 and with the HP1alpha, MODI (HP1beta) and MOD2 (HP1gamma) heterochromatinic proteins, suggesting that they may participate in a complex involved in heterochromatin-induced gene repression, TIF1gamma does not interact with either the KRAB domain of KOX1 or the HP1 proteins. Nevertheless, TIF1gamma, like TIF1alpha and TIF1beta, exhibits a strong silencing activity when tethered to a promoter. Since deletion of a novel motif unique to the three TIF1 proteins, called TIF1 signature sequence (TSS), abrogates transcriptional repression by TIF1gamma, this motif likely participates in TIF1 dependent repression.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromobox Protein Homolog 5
  • Chromosome Banding
  • Chromosome Mapping
  • Cloning, Molecular
  • DNA-Binding Proteins / genetics
  • Gene Expression Regulation
  • Humans
  • Molecular Sequence Data
  • Multigene Family*
  • Nuclear Proteins / genetics
  • Protein Binding
  • RNA, Messenger / isolation & purification
  • Recombinant Proteins / biosynthesis
  • Repressor Proteins / genetics
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Tissue Distribution
  • Transcription Factors / genetics
  • Transcription, Genetic
  • Transfection
  • Tripartite Motif-Containing Protein 28

Substances

  • CBX1 protein, human
  • CBX5 protein, human
  • DNA-Binding Proteins
  • Nuclear Proteins
  • RNA, Messenger
  • Recombinant Proteins
  • Repressor Proteins
  • Transcription Factors
  • transcriptional intermediary factor 1
  • Chromobox Protein Homolog 5
  • TRIM28 protein, human
  • Tripartite Motif-Containing Protein 28

Associated data

  • GENBANK/AF119042
  • GENBANK/AF119043