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Histone modifications influence chromatin structure and thus regulate the accessibility of DNA to replication, recombination, repair, and transcription. We show here that the histone deubiquitinating enzyme Ubp10 contributes to the formation/maintenance of silenced chromatin at the rDNA by affecting Sir2p association.

Abstract Background The integration of data from multiple genome-wide assays is essential for understanding dynamic spatio-temporal interactions within cells. Such integration, which leads to a more complete view of cellular processes, offers the opportunity to rationalize better the high amount of "omics" data freely available in several public databases. In particular, integration of microarray-derived transcriptome data with other high-throughput analyses (genomic and mutational analysis, promoter analysis) may allow us to unravel transcriptional regulatory networks under a variety of physio-pathological situations, such as the alteration in the cross-talk between signal transduction pathways in transformed cells. Results Here we sequentially apply web-based and statistical tools to a case study: the role of oncogenic activation of different signal transduction pathways in the transcriptional regulation of genes encoding proteins involved in the cAMP-PKA pathway. To this end, we first re-analyzed available genome-wide expression data for genes encoding proteins of the downstream branch of the PKA pathway in normal tissues and human tumor cell lines. Then, in order to identify mutation-dependent transcriptional signatures, we classified cancer cells as a function of their mutational state. The results of such procedure were used as a starting point to analyze the structure of PKA pathway-encoding genes promoters, leading to identification of specific combinations of transcription factor binding sites, which are neatly consistent with available experimental data and help to clarify the relation between gene expression, transcriptional factors and oncogenes in our case study. Conclusions Genome-wide, large-scale "omics" experimental technologies give different, complementary perspectives on the structure and regulatory properties of complex systems. Even the relatively simple, integrated workflow presented here offers opportunities not only for filtering data noise intrinsic in high throughput data, but also to progressively extract novel information that would have remained hidden otherwise. In fact we have been able to detect a strong transcriptional repression of genes encoding proteins of cAMP/PKA pathway in cancer cells of different genetic origins. The basic workflow presented herein may be easily extended by incorporating other tools and can be applied even by researchers with poor bioinformatics skills.

The development of a homolactic Kluyveromyces lactis yeast strain, which displays high concentration and high productivity of lactic acid at a pH level below 5 to 5.5, the typical minimum pH range for lactate production by conventional microbial cells, is reported. Results represent the first example of a total replacement of a fermentation product mediated by metabolic engineering methods in yeast genera.

Yest divides through an asymmetrical process. A series of experiments was used to analyze the Po value and the duration of the budded phase in an asynchronously growing Saccharomyces cerevisiae population using a newly developed flow cytometric approach. Results derived during transient states of growth show that the whole population requires a few hours to reach a balanced growth condition. Effects of nutritional shift-down were also determined.

CUG, a universal leucine codon, has been reported to be read as serine in various yeast species belonging to the genus Candida. To gain a deeper insight into the origin of this deviation from the universal genetic code, we carried out a phylogenetic analysis based on the small-subunit ribosomal RNA genes from some Candida and other related Hemiascomycetes. Furthermore, we determined the phylogenetic relationships between the [tRNA.sup.Ser]CAG, responsible for the translation of CUG, from some Candida species and the other serine and leucine isoacceptor tRNAs in C. cylindracea. We demonstrate that the group of Candida showing the genetic code deviation is monophiletic and that this deviation could have been originated more than 150 million years ago. We also describe how phylogenetic analysis can be used for genetic code predictions.

The cyclic AMP signal pathway regulates the dependency of CLN cyclins on cell growth and inhibits CLN1 and CLN2, which encode g1-specific cyclins, thereby inhibiting the growth-regulated expression of G1 cyclin. More growth is required to reinitiate the G1 phase of cell cycle called Start, accounting for the cAMP-dependent rise of the critical size and rate of protein metabolism. However, Cln3, which also encodes G1-specific cyclins, remains unaffected by the cAMP pathway and counteracts cAMP-induced inhibition by regulating the growth-dependent expression of other G1 cyclins.

Researchers have been able to increase the secretion of human insulin-like growth hormone from yeast by fusing the hIGF-1 gene to the prepro-alpha-factor leader sequence and inactivating the GAS1 gene of the yeast. This hormone is of interest to the pharmaceutical industry.

Motivation The elucidation of dysfunctional cellular processes that can induce the onset of a disease is a challenging issue from both the experimental and computational perspectives. Here we introduce a novel computational method based on the coupling between fuzzy logic modeling and a global optimization algorithm, whose aims are to (1) predict the emergent dynamical behaviors of highly heterogeneous systems in unperturbed and perturbed conditions, regardless of the availability of quantitative parameters, and (2) determine a minimal set of system components whose perturbation can lead to a desired system response, therefore facilitating the design of a more appropriate experimental strategy. Results We applied this method to investigate what drives K-ras-induced cancer cells, displaying the typical Warburg effect, to death or survival upon progressive glucose depletion. The optimization analysis allowed to identify new combinations of stimuli that maximize pro-apoptotic processes. Namely, our results provide different evidences of an important protective role for protein kinase A in cancer cells under several cellular stress conditions mimicking tumor behavior. The predictive power of this method could facilitate the assessment of the response of other complex heterogeneous systems to drugs or mutations in fields as medicine and pharmacology, therefore paving the way for the development of novel therapeutic treatments. Availability and implementation The source code of FUMOSO is available under the GPL 2.0 license on GitHub at the following URL: https://github.com/aresio/FUMOSO Supplementary information Supplementary data are available at Bioinformatics online. [ABSTRACT FROM AUTHOR]