cis-acting sequences and trans-acting factors in the localization of mRNA for mitochondrial ribosomal proteins

mRNA localization is a conserved post-transcriptional process crucial for a variety of systems. Although several mechanisms have been identified, emerging evidence suggests that most transcripts reach the protein functional site by moving along cytoskeleton elements. We demonstrated previously that mRNA for mitochondrial ribosomal proteins are asymmetrically distributed in the cytoplasm, and that localization in the proximity of mitochondria is mediated by the 3′-UTR. Here we show by biochemical analysis that these mRNA transcripts are associated with the cytoskeleton through the microtubule network. Cytoskeleton association is functional for their intracellular localization near the mitochondrion, and the 3′-UTR is involved in this cytoskeleton-dependent localization. To identify the minimal elements required for localization, we generated DNA constructs containing, downstream from the GFP gene, deletion mutants of mitochondrial ribosomal protein S12 3′-UTR, and expressed them in HeLa cells. RT-PCR analysis showed that the localization signals responsible for mRNA localization are located in the first 154 nucleotides. RNA pulldown assays, mass spectrometry, and RNP immunoprecipitation assay experiments, demonstrated that mitochondrial ribosomal protein S12 3′-UTR interacts specifically with TRAP1 (tumor necrosis factor receptor-associated protein1), hnRNPM4 (heterogeneous nuclear ribonucleoprotein M4), Hsp70 and Hsp60 (heat shock proteins 70 and 60), and α-tubulin in vitro and in vivo

Mental Well-being Among Workers: A Cross-national Analysis of Job Insecurity Impact on the Workforce

AbstractDrawing on 2011 and 2016European Quality of Life Surveydata from eight European countries, this paper considers the importance of subjective indicators of employment conditions in impacting mental well-being. Among employment conditions, job insecurity has been discussed as having a negative impact on mental well-being by enhancing the worker's sense of unpredictability. The idea of losing one's job brings with it the fear of an uncertain or unclear future and the sense of lack of agency—i.e. feeling powerless with respect to the risk of becoming unemployed. Thus, we investigate two dimensions of job insecurity, namely 'cognitive job insecurity' and 'labour market insecurity'. Our dependent variable is mental health well-being, measured using the 5-item World Health Organization Well-Being Index (WHO-5), which is a self-reported health scale validated by several studies and internationally adopted for measuring psychological well-being. We apply a fixed-effects model and use a set of individual control variables to obtain parameter estimates. Moreover, to control for country-level heterogeneity, two macro-level variables are considered: the type of welfare regime and employment protection. The novelty of this research lies in disentangling the concept of precariousness from the dichotomy of open-ended/non-open-ended contract and in including in the analysis subjective categories such as self-perceived job insecurity. The findings of our study suggest that self-perceived job insecurity is negatively related to mental well-being for both permanent and temporary workers, making this stressor an important feature in predicting the emergence of psychological distress (i.e. feelings of anxiety or depression) among the workforce

Alternative splicing and nonsense-mediated mRNA decay regulate mammalian ribosomal gene expression

Messenger RNAs containing premature stop codons are generally targeted for degradation through nonsense-mediated mRNA decay (NMD). This mechanism degrades aberrant transcripts derived from mutant genes containing nonsense or frameshift mutations. Wild-type genes also give rise to transcripts targeted by NMD. For example, some wild-type genes give rise to alternatively spliced transcripts that are targeted for decay by NMD. In Caenorhabditis elegans, the ribosomal protein (rp) L12 gene generates a nonsense codon-bearing alternatively spliced transcript that is induced in an autoregulatory manner by the rpL12 protein. By pharmacologically blocking the NMD pathway, we identified alternatively spliced mRNA transcripts derived from the human rpL3 and rpL12 genes that are natural targets of NMD. The deduced protein sequence of these alternatively spliced transcripts suggests that they are unlikely to encode functional ribosomal proteins. Overexpression of rpL3 increased the level of the alternatively spliced rpL3 mRNA and decreased the normally expressed rpL3. This indicates that rpL3 regulates its own production by a negative feedback loop and suggests the possibility that NMD participates in this regulatory loop by degrading the non-functional alternatively spliced transcript

Informality in contemporary Cuban labor market. An anthropological perspective

This article shall analyze from a socio-anthropological perspective, and based upon the data collected during ten years of qualitative research in La Habana (2007-2017), the phenomenon of informality in the Cuban contemporary labor market, in both discourse and practice, by considering the structural reasons (political and economic) along with the socio-cultural ones

Autoregulatory circuit of human rpL3 expression requires hnRNP H1, NPM and KHSRP

Alternative pre-mRNA splicing (AS) is a major mechanism that allows proteomic variability in eukaryotic cells. However, many AS events result in mRNAs containing a premature termination codon, which are degraded by nonsense-mediated mRNA decay (NMD) pathway. We have previously demonstrated that human rpL3 autoregulates its expression through the association of AS with NMD. In fact, overexpression of rpL3 promotes downregulation of canonical splicing and upregulation of alternative splicing that produces an NMD-targeted mRNA isoform. The result of these events is a decreased production of rpL3. We have also identified heterogeneous nuclear ribonucleoprotein (hnRNP) H1 as a splicing factor involved in the regulation of rpL3 alternative splicing and identified its regulatory cis-elements within intron 3 transcript. Here, we report that NPM and KHSRP are two newly identified proteins involved in the regulation of rpL3 gene expression via AS-NMD. We demonstrate that hnRNP H1, KHSRP and NPM can be found associated, and present also in ribonucleoproteins (RNPs) including rpL3 and intron 3 RNA in vivo, and describe protein-protein and RNA-protein interactions. Moreover, our data provide an insight on the crucial role of hnRNP H1 in the regulation of the alternative splicing of the rpL3 gene

obtaining a nzeb in mediterranean climate by using only on site renewable energy is it a realistic goal

Abstract A new concept of building is represented by Zero Energy Buildings (ZEBs). This paper evaluates the possibility to obtain a NZEB (for office building) by using only "on-site" renewable energy, solely on the roof. A dynamic energy simulation code, EnergyPlus, is used. Two different Italian climatic zones (Palermo and Naples) and two typologies of building are considered: square or rectangular basis. For the building with square basis, the energy self-sufficiency is kept up to a higher number of the building levels (8 for Naples, 10 for Palermo) compared to the case of rectangular basis (7 levels for Naples, 9 for Palermo)

energy retrofit of historic buildings in the mediterranean area the case of the palaeontology museum of naples

Abstract This paper aims to identify some optimal system solutions for the energy refurbishment of a specific historic building, through energy simulations in dynamic conditions performed with a suitable software. The analysis is carried out by the evaluation of energy requirements of the building, in terms of both primary and electric energy. The hypotheses of intervention regard only the air conditioning system components and take into account the existing architectural constraints. The case study refers to the Palaeontology Museum of Naples (Southern Italy), whose rooms are currently in a historic building located in the ancient centre of the city

Thrombin–aptamer recognition: a revealed ambiguity

Aptamers are structured oligonucleotides that recognize molecular targets and can function as direct protein inhibitors. The best-known example is the thrombin-binding aptamer, TBA, a single-stranded 15-mer DNA that inhibits the activity of thrombin, the key enzyme of coagulation cascade. TBA folds as a G-quadruplex structure, as proved by its NMR structure. The X-ray structure of the complex between TBA and human α-thrombin was solved at 2.9-Å resolution, but did not provide details of the aptamer conformation and the interactions with the protein molecule. TBA is rapidly processed by nucleases. To improve the properties of TBA, a number of modified analogs have been produced. In particular, a modified TBA containing a 5′-5′ polarity inversion site, mTBA, has higher stability and higher affinity toward thrombin with respect to TBA, although it has a lower inhibitory activity. We present the crystal structure of the thrombin–mTBA complex at 2.15-Å resolution; the resulting model eventually provides a clear picture of thrombin–aptamers interaction, and also highlights the structural bases of the different properties of TBA and mTBA. Our findings open the way for a rational design of modified aptamers with improved potency as anticoagulant drugs

Prevalence and type distribution of human papillomavirus infection among women with different degrees of cervical cytological abnormalities in Sicily (Italy)

Human papillomaviruses (HPVs) are etiological agents of cervical cancer. In the absence of Pap smear alterations, high-risk HPV DNA can be detected in cervical samples. The prevalence of papillomavirus infection and their genotype distribution varies greatly across populations. The aims of this study were: i) to assess the prevalences of HPV genotypes in people living in Eastern Sicily (Italy) and the frequency of HPV multiple infections; ii) to evaluate the association between HPV genotypes and cervical lesions in order to improve the epidemiological knowledge useful for monitoring or treating infected women. Nested PCR and reverse dot/blot hybridization were used for the detection and typing of HPV DNA in 315 women who had had an abnormal PAP-smear. HPV DNA test was positive in 70.5% cases; the prevalence was 50% in atypical squamous cells of undetermined significance (ASCUS), 80.8% in low grade-, and 76.2% in high grade-squamous intraepithelial lesion (H-SIL). The genotype distribution showed a predominance of HPV-16 (56.7%) followed by HPV-18 (12.2%), HPV-31 (9.5%) and HPV-6 (9.5%). Multiple infections were detected in 35.1% of the infected patients. High frequency of positive results for HPV was confirmed and, even in case of ASCUS, patients should be taken into account for genotyping. Our data indicate that multiple infections are consistent in women with low-grade lesions while they are less frequent in women with H-SIL. This could reinforce the theory of the multi-stage cancer model, by which one HPV type becomes predominant along with the progression of cervical lesion severity