Histone Crosstalk between H2B Monoubiquitination and H3 Methylation Mediated by COMPASS

kavin submitted, created time 1 year 3 weeks (www.cell.com)

"COMPASS, the yeast homolog of the mammalian MLL complex, is a histone H3 lysine 4 (H3K4) methylase consisting of Set1 (KMT2) and seven other polypeptides, including Cps35, the only essential subunit. Histone H2B monoubiquitination by Rad6/Bre1 is required for both H3K4 methylation by COMPASS, and H3K79 methylation by Dot1. However, the molecular mechanism for such histone crosstalk is poorly understood. Here, they demonstrate that histone H2B monoubiquitination controls the binding of Cps35 with COMPASS complex

1 comment | Blog It | Email It | Keywords: histone acetylation histone-modification maps DNA crosstalk histone methyltransferase histones

TRRAP and GCN5 are used by c-Myc to activate RNA polymerase III transcription

benjiamin submitted, created time 1 year 3 months (www.pnas.org)

Activation of RNA polymerase (pol) II transcription by c-Myc generally involves recruitment of histone acetyltransferases and acetylation of histones H3 and H4. Here, we describe the mechanism used by c-Myc to activate pol III transcription of tRNA and 5S rRNA genes.

1 comment | Blog It | Email It | Keywords: TRRAP GCN5 RNA polymerase III transcription activate RNA polymerase III histone acetylation TRRAP GCN5 c-Myc

In Vivo Effects of Cyclooxygenase-2 Deletion on Cellular Signaling in Hepatocellular Carcinoma Xenografts in Nude Mice

Histone Chaperone-Dependent Complexes Catalyze Histone H3-K56 Acetylation

addict submitted, created time 1 year 9 months (www.sciencedirect.com)

“Acetylation of histone H3 on lysine 56 occurs during mitotic and meiotic S phase in fungal species. This acetylation blocks a direct electrostatic interaction between histone H3 and nucleosomal DNA, and the absence of this modification is associated with extreme sensitivity to genotoxic agents. H3-K56 acetylation is catalyzed when Rtt109, a protein that lacks significant homology to known acetyltransferases, forms an active complex with either of two histone binding proteins, Asf1 or Vps75

1 comment | Blog It | Email It | Keywords: histone acetylation

Telomere length and heterochromatin

yoyotaxi submitted, created time 1 year 10 months (www.nature.com)

The research report that mice with short telomeres show decreased histone trimethylation and increased histone acetylation in telomeric and subtelomeric chromatin. The authors suggest that maintenance of telomeric repeats is required for the establishment of constitutive heterochromatin in these regions.

1 comment | Blog It | Email It | Keywords: Telomere heterochromatin histone trimethylation histone acetylation subtelomeric chromatin