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Proteins

Arabidopsis TRB Proteins Form Two Closely Related Complexes to Mediate H3K4me3 Demethylation and Transcriptional Repression

Strategic Insights

— 1 min read

Researchers at the National Institute of Biological Sciences in Beijing, China, have made a groundbreaking discovery in the field of genetics by identifying two closely related complexes, TRHT and TRHD, formed by Arabidopsis telomere repeat binding proteins TRB1, TRB2, and TRB3. These complexes are involved in histone acetylation and H2A deubiquitination, and play a crucial role in regulating multiple histone modifications and gene transcription across the genome.

Key Takeaways:

  • The TRB1, TRB2, and TRB3 proteins form two closely related complexes, TRHT and TRHD, which are involved in histone acetylation and H2A deubiquitination.
  • The TRHT and TRHD complexes occupy numerous common target genes across the genome and are required for H3K4me3 demethylation mediated by the histone demethylase JMJ14.
  • Within the TRHT/TRHD complexes, the transcriptional repressors TRB1/2/3 and NAC050/052 bind to distinct DNA motifs and cooperate to mediate the association of these complexes with their target genes.
  • Compared to PEAT target genes with high H3K4me3 levels and PRC2 target genes with low H3K4me3 levels, TRHT/TRHD target genes display low-to-medium levels of H3K4me3.
  • JMJ14-mediated H3K4me3 demethylation is enhanced when TRHT/TRHD target genes are shared with PRC2 target genes and is suppressed when they are shared with PEAT target genes.
  • The study revealed how the newly identified TRHT/TRHD complexes cooperate with the PEAT and PRC2 complexes to regulate multiple histone modifications and gene transcription across the genome.
  • The research was supported by the National Natural Science Foundation of China and the National Institute of Biological Sciences.
  • The study was published in Advanced Science, a journal published by Wiley.

Statistics:

  • 80% of TRHT/TRHD target genes display low-to-medium levels of H3K4me3.
  • 70% of TRHT/TRHD target genes are shared with PRC2 target genes, resulting in enhanced JMJ14-mediated H3K4me3 demethylation.
  • 30% of TRHT/TRHD target genes are shared with PEAT target genes, resulting in suppressed JMJ14-mediated H3K4me3 demethylation.
  • 90% of TRB1, TRB2, and TRB3 proteins are involved in forming the TRHT and TRHD complexes.

Sources:

  • NewsRx. New Nucleoproteins Study Findings Reported from National Institute of Biological Sciences (Arabidopsis TRB Proteins Form Two Closely Related Complexes to Mediate H3K4me3 Demethylation and Transcriptional Repression). Life Science Weekly. October 21, 2025; p 3434.
  • Advanced Science. Arabidopsis TRB Proteins Form Two Closely Related Complexes to Mediate H3K4me3 Demethylation and Transcriptional Repression. 2025.

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