Dual chromatin remodeling roles for RSC during DNA double strand break induction and repair at the yeast MAT locus

The contribution of the budding yeast histone H2A C-terminal tail to DNA-damage responses

The cellular response to DNA damage involves extensive interaction with and manipulation of chromatin. This includes the detection and repair of the DNA lesion, but there are also transcriptional responses to DNA damage, involving the up- or down-regulation of numerous genes. Therefore changes to chromatin structure, including covalent modification of histone proteins, are known to occur during DNA-damage responses. One of the most well characterized DNA-damage-responsive chromatin modification events is the phosphorylation of the SQ motif found in the C-terminal tail of histone H2A or the H2AX variant in higher eukaryotes. In the budding yeast, a number of additional residues in this region of histone H2A that contribute to the cellular response to DNA damage have been identified, providing an insight into the nature and complexity of the DNA-damage histone code.

Histone chaperones: an escort network regulating histone traffic

In eukaryotes, DNA is organized into chromatin in a dynamic manner that enables it to be accessed for processes such as transcription and repair. Histones, the chief protein component of chromatin, must be assembled, replaced or exchanged to preserve or change this organization according to cellular needs. Histone chaperones are key actors during histone metabolism. Here we classify known histone chaperones and discuss how they build a network to escort histone proteins. Molecular interactions with histones and their potential specificity or redundancy are also discussed in light of chaperone structural properties. The multiplicity of histone chaperone partners, including histone modifiers, nucleosome remodelers and cell-cycle regulators, is relevant to their coordination with key cellular processes. Given the current interest in chromatin as a source of epigenetic marks, we address the potential contributions of histone chaperones to epigenetic memory and genome stability.