ATXN7L3 and ENY2 Coordinate Activity of Multiple H2B Deubiquitinases Important for Cellular Proliferation and Tumor Growth.

Histone H2B monoubiquitination (H2Bub1) is centrally involved in gene regulation. The deubiquitination module (DUBm) of the SAGA complex is a major regulator of global H2Bub1 levels, and components of this DUBm are linked to both neurodegenerative diseases and cancer. Unexpectedly, we find that ablation of USP22, the enzymatic center of the DUBm, leads to a reduction, rather than an increase, in global H2bub1 levels.

Expanded complexity of unstable repeat diseases.

Unstable repeat diseases (URDs) share a common mutational phenomenon of changes in the copy number of short, tandemly repeated DNA sequences. More than 20 human neurological diseases are caused by instability, predominantly, expansion of microsatellite sequences. Changes in the repeat size initiate a cascade of pathological processes, frequently characteristic of a unique disease or a small subgroup of the URDs.

2,6-Dithiopurine, a nucleophilic scavenger, protects against mutagenesis in mouse skin treated in vivo with 2-(chloroethyl) ethyl sulfide, a mustard gas analog.

Sulfur mustard [bis(2-chloroethyl)sulfide, SM] is a well-known DNA-damaging agent that has been used in chemical warfare since World War I, and is a weapon that could potentially be used in a terrorist attack on a civilian population. Dermal exposure to high concentrations of SM produces severe, long-lasting burns. Topical exposure to high concentrations of 2-(chloroethyl) ethyl sulfide (CEES), a monofunctional analog of SM, also produces severe skin lesions in mice.

New insights into repeat instability: role of RNA•DNA hybrids.

Expansion of tandem repeat sequences is responsible for more than 20 human diseases. Several cis elements and trans factors involved in repeat instability (expansion and contraction) have been identified. However no comprehensive model explaining large intergenerational or somatic changes of the length of the repeating sequences exists.