Preparing your results

Our searching services are busy right now. Your search will reload in five seconds.

X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Ubiquitination of histone H2B regulates H3 methylation and gene silencing in yeast.

Nature | Jul 4, 2002

http://www.ncbi.nlm.nih.gov/pubmed/12077605

In eukaryotes, the DNA of the genome is packaged with histone proteins to form nucleosomal filaments, which are, in turn, folded into a series of less well understood chromatin structures. Post-translational modifications of histone tail domains modulate chromatin structure and gene expression. Of these, histone ubiquitination is poorly understood. Here we show that the ubiquitin-conjugating enzyme Rad6 (Ubc2) mediates methylation of histone H3 at lysine 4 (Lys 4) through ubiquitination of H2B at Lys 123 in yeast (Saccharomyces cerevisiae). Moreover, H3 (Lys 4) methylation is abolished in the H2B-K123R mutant, whereas H3-K4R retains H2B (Lys 123) ubiquitination. These data indicate a unidirectional regulatory pathway in which ubiquitination of H2B (Lys 123) is a prerequisite for H3 (Lys 4) methylation. We also show that an H2B-K123R mutation perturbs silencing at the telomere, providing functional links between Rad6-mediated H2B (Lys 123) ubiquitination, Set1-mediated H3 (Lys 4) methylation, and transcriptional silencing. Thus, these data reveal a pathway leading to gene regulation through concerted histone modifications on distinct histone tails. We refer to this as 'trans-tail' regulation of histone modification, a stated prediction of the histone code hypothesis.

Pubmed ID: 12077605 RIS Download

Mesh terms: Alleles | Blotting, Western | Chromatin | Gene Expression Regulation, Fungal | Gene Silencing | Histone-Lysine N-Methyltransferase | Histones | Ligases | Methylation | Methyltransferases | Mutation | Phenotype | Protein Methyltransferases | RNA, Fungal | RNA, Messenger | Saccharomyces cerevisiae | Saccharomyces cerevisiae Proteins | Telomere | Ubiquitin | Ubiquitin-Conjugating Enzymes