Intrinsic disorder of a nucleoplasmin-like histone chaperone specifies its discrete nuclear and nucleolar functions.

Nucleoplasmin (NPM) histone chaperones regulate distinct processes in the nucleus and nucleolus. While intrinsically disordered regions (IDRs) are hallmarks of NPMs, it is not clear whether all NPM functions require these unstructured features. We assessed the importance of IDRs in a yeast NPM-like protein and found that regulation of rDNA copy number and genetic interactions with the nucleolar RNA surveillance machinery require the highly conserved FKBP prolyl isomerase domain, but not the NPM domain or IDRs.

Histone Chaperone Paralogs Have Redundant, Cooperative, and Divergent Functions in Yeast.

Gene duplications increase organismal robustness by providing freedom for gene divergence or by increasing gene dosage. The yeast histone chaperones Fpr3 and Fpr4 are paralogs that can assemble nucleosomes ; however, the genomic locations they target and their functional relationship is poorly understood. We refined the yeast synthetic genetic array approach to enable the functional dissection of gene paralogs.

Replication Rapidly Recovers and Continues in the Presence of Hydroxyurea in Escherichia coli.

In both prokaryotes and eukaryotes, hydroxyurea is suggested to inhibit DNA replication by inactivating ribonucleotide reductase and depleting deoxyribonucleoside triphosphate pools. In this study, we show that the inhibition of replication in is transient even at concentrations of 0.1 M hydroxyurea and that replication rapidly recovers and continues in its presence.

Basic surface features of nuclear FKBPs facilitate chromatin binding.

The nucleoplasmin family of histone chaperones is identified by a pentamer-forming domain and multiple acidic tracts that mediate histone binding and chaperone activity. Within this family, a novel domain organization was recently discovered that consists of an N-terminal nucleoplasmin-like (NPL) domain and a C-terminal FKBP peptidyl-proline isomerase domain. Saccharomyces cerevisiae Fpr4 is one such protein.