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The paper aims to describe the Information Structure (IS) of Romanian negative statements by using an F0 contour interpretation at the cognitive level. The IS analysis of contours is based on a cognitive (pre-linguistic) model. The descriptions of IS partitions deduced from F0 contours are then related to the semantic aspects of the negation phenomenon: the phrase accent and the focus position of the new information element within the rheme part of sentence. Important prosodic characteristics are added to those presented in Dascălu-Jinga 2001 şi Dascălu-Jinga 1998 related to Romanian intonational contours of negative sentence utterances. The new aspect introduced by the paper in the F0 contour analysis is the cognitive IS model which interprets melodic forms of prosodic words as functional element marks. In section 2 the IS model at the cognitive level is presented by defining information unit, the two structural levels and nuclear accent rules. The model can describe a cognitive reality of information packaging within utterances that is different from the syntactic and semantic organization of sentences. In section 3 are presented 5 utterances of negative sentences. After their F0 contours partitioning, IS model-based descriptions are applied to the resulted partitions and they can explain how is implemented at the pragmatic level the semantic focus function of the constituent which is responsible from the non-realization of the action within negative sentence. The examples of negative sentences include cases where the negation particle bears only acoustic prominence (constituent negation) and others, where it also bears functional prominence at the cognitive and semantic IS level. In the latter case, the particle nu negates the whole sentence and it has a positive acoustical prominence (melodic peak) and a functional prominence at the cognitive and semantic level. The F0 contour analysis leads to the conclusion that focus event usually shares the same position with the nuclear element within one partition but there are cases when they have different positions. This is an argument to treat them as different structural aspects of utterances at the semantic level and at the information packaging level, respectively. We conclude that the paper is useful for students and linguist researchers who are interested to deepen the comprehension of the pragmatic realization of the negation phenomenon within Romanian utterances by identifying the IS partition hierarchy of utterances at the cognitive level, including local and global nuclear elements. [ABSTRACT FROM AUTHOR]

Aminoacyl tRNA synthetases (AARSs) are best known for their essential role in translation in the cytoplasm. The concept that AARSs also exist in the nucleus started to draw attention around the turn of the new millennium, when aminoacylated tRNAs were first found in the nuclei of Xenopus oocytes. It is now expected that all cytoplasmic AARSs are present in the nucleus. In addition to tRNA aminoacylation, nuclear AARSs were found to regulate a spectrum of biological processes and responses, with many AARSs functioning through regulation at the level of gene transcription. In this paper, we focus on describing methods that have been successfully implemented to study AARSs in transcriptional regulation. These include a cell fractionation assay to detect nuclear localization, an in vitro DNA-cellulose pull-down assay to determine DNA binding capacity, and a chromatin immunoprecipitation (ChIP)-DNA deep sequencing assay to identify DNA binding sites. Application of these methods would expand our understanding of AARS functions and reveal critical insights on the coordination of gene transcription and translation. [ABSTRACT FROM AUTHOR]

The finding that small non-coding RNAs (ncRNAs) are able to control gene expression in a sequence specific manner has had a massive impact on biology. Recent improvements in high throughput sequencing and computational prediction methods have allowed the discovery and classification of several types of ncRNAs. Based on their precursor structures, biogenesis pathways and modes of action, ncRNAs are classified as small interfering RNAs (siRNAs), microRNAs (miRNAs), PIWI-interacting RNAs (piRNAs), endogenous small interfering RNAs (endo-siRNAs or esiRNAs), promoter associate RNAs (pRNAs), small nucleolar RNAs (snoRNAs) and sno-derived RNAs. Among these, miRNAs appear as important cytoplasmic regulators of gene expression. miRNAs act as post-transcriptional regulators of their messenger RNA (mRNA) targets via mRNA degradation and/or translational repression. However, it is becoming evident that miRNAs also have specific nuclear functions. Among these, the most studied and debated activity is the miRNA-guided transcriptional control of gene expression. Although available data detail quite precisely the effectors of this activity, the mechanisms by which miRNAs identify their gene targets to control transcription are still a matter of debate. Here, we focus on nuclear functions of miRNAs and on alternative mechanisms of target recognition, at the promoter lavel, by miRNAs in carrying out transcriptional gene silencing. [ABSTRACT FROM AUTHOR]

Drosophila Ceramide Synthase (CerS) Schlank regulates both ceramide synthesis and fat metabolism. Schlank contains a catalytic lag1p motif and, like many CerS in other species, a homeodomain of unknown function. Here, we show that the Drosophila CerS Schlank is imported into the nucleus and requires two nuclear localization signals ( NLSs) within its homeodomain and functional Importin-β import machinery. Expression of Schlank variants containing the homeodomain without functional lag1p motif rescued the fat metabolism phenotype of schlank mutants whereas a variant with a mutated NLS site did not rescue. Thus, the homeodomain of Schlank is involved in the regulation of lipid metabolism independent of the catalytic lag1p motif. [ABSTRACT FROM AUTHOR]

Abstract: Glutathione (GSH) is considered the most important redox buffer of the cell. To better characterize its essential function during oxidative stress conditions, we studied the physiological response of H2O2-treated yeast cells containing various amounts of GSH. We showed that the transcriptional response of GSH-depleted cells is severely impaired, despite an efficient nuclear accumulation of the transcription factor Yap1. Moreover, oxidative stress generates high genome instability in GSH-depleted cells, but does not activate the checkpoint kinase Rad53. Surprisingly, scarce amounts of intracellular GSH are sufficient to preserve cell viability under H2O2 treatment. In these cells, oxidative stress still causes the accumulation of oxidized proteins and the inactivation of the translational activity, but nuclear components and activities are protected against oxidative injury. We conclude that the essential role of GSH is to preserve nuclear function, allowing cell survival and growth resumption after oxidative stress release. We propose that cytosolic proteins are part of a protective machinery that shields the nucleus by scavenging reactive oxygen species before they can cross the nuclear membrane. [Copyright &y& Elsevier]

The DSL1 complex is a conserved tethering complex at the endoplasmic reticulum that recognizes Golgi-derived COPI vesicles and hands them over to the fusion machinery. The DSL1 complex is the simplest tethering complex of the complexes associated with tethering containing helical rods ( CATCHR) family. CATCHR tethering complexes play a role at compartments along the exocytic and endocytic pathways. In this review, different functions of the DSL1 complex are discussed, some open questions with the seemingly straightforward picture are pointed out and alternative functions of the DSL1 complex members are mentioned. [ABSTRACT FROM AUTHOR]