PVT1: a rising star among oncogenic long non-coding RNAs

It is becoming increasingly clear that short and long noncoding RNAs critically participate in the regulation of cell growth, differentiation, and (mis)function. However, while the functional characterization of short non-coding RNAs has been reaching maturity, there is still a paucity of well characterized long noncoding RNAs, even though large studies in recent years are rapidly increasing the number of annotated ones. The long noncoding RNA PVT1 is encoded by a gene that has been long known since it resides in the well-known cancer risk region 8q24. However, a couple of accidental concurrent conditions have slowed down the study of this gene, that is, a preconception on the primacy of the protein-coding over noncoding RNAs and the prevalent interest in its neighbor MYC oncogene. Recent studies have brought PVT1 under the spotlight suggesting interesting models of functioning, such as competing endogenous RNA activity and regulation of protein stability of important oncogenes, primarily of the MYC oncogene. Despite some advancements in modelling the PVT1 role in cancer, there are many questions that remain unanswered concerning the precise molecular mechanisms underlying its functioning

In vivo site-directed mutagenesis of Neurospora crassa beta-tubulin gene by spheroplasts transformation with oligonucleotides

The use of Polymerase Chain Reaction (PCR) to incorporate mutated oligonucleotides into newly synthesized segments of DNA and the subsequent introduction of this DNA into competent cells is one of the most widely used methods of site-directed mutagenesis (Zoller et al.1984 DNA 3:479-488; Dalbodie-McFarland et al. 1982 Proc. Natl. Acad. Sci. USA 79:6409-6413). Several variations of this technique exist, but all require several and some time-consuming steps. Here we report the results of a rapid method of in vivo site-directed mutagenesis involving the direct transformation of Neurospora crassa spheroplasts with mutated oligonucleotides

Internal translation initiation in the mRNA for the Neurospora crassa albino-3 gene

The "ribosome scanning model" for translational initiation predicts that eukaryotic mRNAs should, as a rule, be monocistronic. However, cases have recently been described of eukaryotic mRNAs producing more than one protein through alternative translational initiation at several different AUG codons. The present work reports the occurrence of multiple translational start sites on the mRNA of the Neurospora crassa gene albino-3 (al-3), encoding the carotenoid biosynthetic enzyme geranylgeranyl-pyrophosphate synthase. This was revealed by the molecular analysis of an al-3 mutant carrying a deletion within the coding sequence, which was expected to prevent the synthesis of a functional geranylgeranyl-pyrophosphate synthase because of ribosome frameshifting and premature translational termination. However, the mutants could maintain appreciable geranylgeranyl-pyrophosphate synthase activity through a mechanism operating at the translational level, whereby a fraction of ribosomes initiated protein synthesis from either of two internal in-frame AUG codons located downstream of the deletion, thus producing a shortened but still active version of the geranylgeranyl-pyrophosphate synthase. The results presented indicate that the internal AUG codons are recognized mainly or solely by direct ribosome binding rather than by "leaky scanning" from the 5' end of the mRNA.The "ribosome scanning model" for translational initiation predicts that eukaryotic mRNAs should, as a rule, be monocistronic. However, cases have recently been described of eukaryotic mRNAs producing more than one protein through alternative translational initiation at several different AUG codons. The present work reports the occurrence of multiple translational start sites on the mRNA of the Neurospora crassa gene albino-3 (al-3), encoding the carotenoid biosynthetic enzyme geranylgeranyl-pyrophosphate synthase. This was revealed by the molecular analysis of an al-3 mutant carrying a deletion within the coding sequence, which was expected to prevent the synthesis of a functional geranylgeranyl-pyrophosphate synthase because of ribosome frameshifting and premature translational termination. However, the mutants could maintain appreciable geranylgeranyl-pyrophosphate synthase activity through a mechanism operating at the translational level, whereby a fraction of ribosomes initiated protein synthesis from either of two internal in-frame AUG codons located downstream of the deletion, thus producing a shortened but still active version of the geranylgeranyl-pyrophosphate synthase. The results presented indicate that the internal AUG codons are recognized mainly or solely by direct ribosome binding rather than by "leaky scanning" from the 5' end of the mRNA

Sulla storiografia giuridica europea dell’Ottocento in tema di diritto longobardo

The relationship between Lombard and Roman law has been the centre of important debates among Italian and German scholars during the 19th century. In particular, the attention drawn by the celebrated writer Alessandro Manzoni on the condition of the conquered people under Lombard rule gave rise to scholarly quarrels, which were sometimes biased by the national pride heightened by the contemporary political background. Other European legal historians, though, have all but rarely entered into such questions, whose nationalistic pattern was clearly perceived even at the time: few of the French followers of the German historical school of law treated the subject, albeit significantly, and only a shallow reflection of it touched the Angloamerican tradition of historical studie

CBM1, a Neurospora crassa genomic cosmid library in pAC3 and its use for walking on the right arm of linkage group VII

Gene cloning in Neurospora crassa is often achieved by mutant complementation. However, the cloning strategy sometimes requires the isolation of a specific genomic region (by chromosome walking) before transformation of N. crassa. This is the case, for example, if the gene to be isolated has a non-selectable phenotype. Here we specifically describe the construction of the cosmid vector, pAC3, which is designed for direct transformation of N. crassa, its utilization for the construction of a genomic library, and chromosome walking in the region of un-10 on linkage group VII

Cosmids from the Vollmer-Yanofsky library identified with a chromosome VII probe.

In microorganisms, genes can often be cloned directly by complementation of mutants with a genomic library

Internal translational initiation in the mRNA from the Neurospora crassa albino-3 gene.

The "ribosome scanning model" for translational initiation predicts that eukaryotic mRNAs should, as a rule, be monocistronic. However, cases have recently been described of eukaryotic mRNAs producing more than one protein through alternative translational initiation at several different AUG codons. The present work reports the occurrence of multiple translational start sites on the mRNA of the Neurospora crassa gene albino-3 (al-3), encoding the carotenoid biosynthetic enzyme geranylgeranyl-pyrophosphate synthase. This was revealed by the molecular analysis of an al-3 mutant carrying a deletion within the coding sequence, which was expected to prevent the synthesis of a functional geranylgeranyl-pyrophosphate synthase because of ribosome frameshifting and premature translational termination. However, the mutants could maintain appreciable geranylgeranyl-pyrophosphate synthase activity through a mechanism operating at the translational level, whereby a fraction of ribosomes initiated protein synthesis from either of two internal in-frame AUG codons located downstream of the deletion, thus producing a shortened but still active version of the geranylgeranyl-pyrophosphate synthase. The results presented indicate that the internal AUG codons are recognized mainly or solely by direct ribosome binding rather than by "leaky scanning" from the 5' end of the mRNA

Continual Cross-Dataset Adaptation in Road Surface Classification

Accurate road surface classification is crucial for autonomous vehicles (AVs) to optimize driving conditions, enhance safety, and enable advanced road mapping. However, deep learning models for road surface classification suffer from poor generalization when tested on unseen datasets. To update these models with new information, also the original training dataset must be taken into account, in order to avoid catastrophic forgetting. This is, however, inefficient if not impossible, e.g., when the data is collected in streams or large amounts. To overcome this limitation and enable fast and efficient cross-dataset adaptation, we propose to employ continual learning finetuning methods designed to retain past knowledge while adapting to new data, thus effectively avoiding forgetting. Experimental results demonstrate the superiority of this approach over naive finetuning, achieving performance close to fresh retraining. While solving this known problem, we also provide a general description of how the same technique can be adopted in other AV scenarios. We highlight the potential computational and economic benefits that a continual-based adaptation can bring to the AV industry, while also reducing greenhouse emissions due to unnecessary joint retraining.Comment: To be published in Proceedings of 26th IEEE International Conference on Intelligent Transportation Systems (ITSC 2023

The oncogenic role of circPVT1 in head and neck squamous cell carcinoma is mediated through the mutant p53/YAP/TEAD transcription-competent complex

Background: Circular RNAs are a class of endogenous RNAs with various functions in eukaryotic cells. Worthy of note, circular RNAs play a critical role in cancer. Currently, nothing is known about their role in head and neck squamous cell carcinoma (HNSCC). The identification of circular RNAs in HNSCC might become useful for diagnostic and therapeutic strategies in HNSCC. Results: Using samples from 115 HNSCC patients, we find that circPVT1 is over-expressed in tumors compared to matched non-tumoral tissues, with particular enrichment in patients with TP53 mutations. circPVT1 up-and down-regulation determine, respectively, an increase and a reduction of the malignant phenotype in HNSCC cell lines. We show that circPVT1 expression is transcriptionally enhanced by the mut-p53/YAP/TEAD complex. circPVT1 acts as an oncogene modulating the expression of miR-497-5p and genes involved in the control of cell proliferation. Conclusions: This study shows the oncogenic role of circPVT1 in HNSCC, extending current knowledge about the role of circular RNAs in cancer

Tuning the activity of supported metal catalysts

This research intends to explore strategies able to modify the activity of heterogeneous catalysts, in order to draw structure-activity relationships and gain an improved understanding of the catalytically active sites. Different approaches have been attempted, such as applying an activation treatment, modifying the metal loading, changing the support and adding organic ligands. These methods have been applied to supported noble metal nanoparticles of Pt, Pd and bimetallic AuPd, which have been previously found active for liquid-phase hydrogenation and oxidation reactions such as the reduction of nitro compounds and the oxidation of alcohols. Several characterisation methods were applied to study the structure and properties of these materials. First, a Pt/TiO2 catalyst for the selective hydrogenation of 3-nitrostyrene has been developed by optimising the effect of the variation of metal loading and heat treatment. In particular, a series of catalysts were prepared, tested and characterised, showing that combining the choice of metal loading (from 0.05 to 0.5%Pt) and activation treatment (reduction or calcination followed by reduction at 450 °C) leads to what shows to be the most active catalyst reported so far. The data acquired by several characterisation techniques such as STEM, XPS, XAS and CO adsorption led to the conclusion that particle size and distribution as well as the environment surrounding the active site affect the catalytic activity and a delicate balance between them needs to be achieved. Then, the role of the support on the catalytic activity of AuPd nanoparticles for the oxidation of glycerol was investigated. Different hydrothermal carbon materials, which derive from biomass and presenting different structural and elemental characteristics were applied as supports. Overall, the amount of oxygen in the structure as well as the curvature of the surface of the hydrothermal carbons showed to have an effect on the glycerol conversion either due to the variation in electron mobility that would favour adsorption of the reactants, or to the strain arising from the lattice mismatch at the metal-support interface. At last, N-heterocyclic carbene ligands were added to a 1% Pd/TiO2 catalyst. The presence of the ligand on the surface of the catalyst has been confirmed and found to be in both a neutral and protonated form. The results obtained by testing these catalysts for the hydrogenation of 3- nitrostyrene and the direct synthesis of hydrogen peroxide suggest that catalytic performance can be affected by either a geometric effect, where active sites are blocked, or by an electronic effect, due to the electronic interaction of the ligands and the Pd nanoparticles. Overall, to develop catalytic materials and improve industrial processes, the reactivity of nanoparticles needs to be maximised, by using strategies that tune their structural and electronic properties