The programme of DNA replication: beyond genome duplication. Gomez-Escoda B and Wu PY Biochemical Society Transactions 41:1720-1725



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The accurate duplication and transmission of genetic information is critical for cell growth and proliferation, and this is ensured in part by the multilayered regulation of DNA synthesis. One of the key steps in this process is the selection and activation of the sites of replication initiation, or origins, across the genome. Interestingly, origin usage changes during development and in different pathologies, suggesting an integral interplay between the establishment of replication initiation along the chromosomes and cellular function. The present review discusses how the spatiotemporal organization of replication origin activation may play crucial roles in the control of biological events.

Quantitative Control of Protein S-Palmitoylation Regulates Meiotic Entry in Fission Yeast Zhang MM, Wu PY, Kelly FD, Nurse P and Hang HC PLOS Biology 11:e1001597



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Protein S-palmitoylation, a lipid modification mediated by members of the palmitoyltransferase family, serves as an important membrane-targeting mechanism in eukaryotes. Although changes in palmitoyltransferase expression are associated with various physiological and disease states, how these changes affect global protein palmitoylation and cellular function remains unknown. Using a bioorthogonal chemical reporter and labeling strategy to identify and analyze multiple cognate substrates of a single Erf2 palmitoyltransferase, we demonstrate that control of Erf2 activity levels underlies the differential modification of key substrates such as the Rho3 GTPase in vegetative and meiotic cells. We show further that modulation of Erf2 activity levels drives changes in the palmitoylome as cells enter meiosis and affects meiotic entry. Disruption of Erf2 function delays meiotic entry, while increasing Erf2 palmitoyltransferase activity triggers aberrant meiosis in sensitized cells. Erf2-induced meiosis requires the function of the Rho3 GTPase, which is regulated by its palmitoylation state. We propose that control of palmitoyltransferase activity levels provides a fundamental mechanism for modulating palmitoylomes and cellular functions.

Insights from a new tool for meiotic induction in fission yeast Wu PY Cell Cycle 11:2050



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Meiosis is the differentiation pathway by which diploid cells produce haploid progeny for sexual reproduction. This specialized process involves one round of DNA replication, exchange of genetic material through recombination and haploidization achieved by two consecutive nuclear divisions without an intervening S phase. Meiosis is a tightly regulated process, and the major steps in meiotic progression, including the duplication, recombination and segregation of the genome, are conserved among eukaryotes. The molecular mechanisms underlying these events have been the subject of extensive and fruitful investigations, in particular in two model systems, the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe. In a previous issue of Cell Cycle, Guerra-Moreno and colleagues presented a novel method for the synchronous induction of meiosis in fission yeast and this approach to uncover new aspects of the meiosis-specific transcriptional program.