Nuku, a family of primate retrocopies derived from KU70.

The gene encoding the ubiquitous DNA repair protein, Ku70p, has undergone extensive copy number expansion during primate evolution. Gene duplications of KU70 have the hallmark of long interspersed element-1 mediated retrotransposition with evidence of target-site duplications, the poly-A tails, and the absence of introns. Evolutionary analysis of this expanded family of KU70-derived "NUKU" retrocopies reveals that these genes are both ancient and also actively being created in extant primate species.

Evolution and Functional Trajectory of Sir1 in Gene Silencing.

We used the budding yeasts Saccharomyces cerevisiae and Torulaspora delbrueckii to examine the evolution of Sir-based silencing, focusing on Sir1, silencers, the molecular topography of silenced chromatin, and the roles of SIR and RNA interference (RNAi) genes in T. delbrueckii. Chromatin immunoprecipitation followed by deep sequencing (ChIP-Seq) analysis of Sir proteins in T.

The Chromatin and Transcriptional Landscape of Native Saccharomyces cerevisiae Telomeres and Subtelomeric Domains.

Saccharomyces cerevisiae telomeres have been a paradigm for studying telomere position effects on gene expression. Telomere position effect was first described in yeast by its effect on the expression of reporter genes inserted adjacent to truncated telomeres. The reporter genes showed variable silencing that depended on the Sir2/3/4 complex.

Direct regulation of nucleosome density by the conserved AAA-ATPase Yta7.

Yta7 is a highly conserved bromodomain-containing protein with AAA-ATPase homology originally implicated in heterochromatin boundary function in Saccharomyces cerevisiae. Although increased activity of the human ortholog has been implicated in malignant breast tumors, Yta7's precise mode of action is unknown. Transcriptional analysis in yeast cells revealed a role for Yta7 and its ATPase function in gene induction, including galactose- and sporulation-induced transcription.