During evolution, new open reading frames (ORFs) with the potential to give rise to novel proteins continuously emerge. A recent compilation of noncanonical ORFs with translation signatures in humans has identified thousands of cases with a putative de novo origin. However, it is not known which is their distribution in the population.
View Article and Find Full Text PDFThe formation of new genes during evolution is an important motor of functional innovation, but the rate at which new genes originate and the likelihood that they persist over longer evolutionary periods are still poorly understood questions. Two important mechanisms by which new genes arise are gene duplication and de novo formation from a previously noncoding sequence. Does the mechanism of formation influence the evolutionary trajectories of the genes? Proteins arisen by gene duplication retain the sequence and structural properties of the parental protein, and thus they may be relatively stable.
View Article and Find Full Text PDFThe unicellular yeast (fission yeast) retains many of the splicing features observed in humans and is thus an excellent model to study the basic mechanisms of splicing. Nearly half the genes contain introns, but the impact of alternative splicing in gene regulation and proteome diversification remains largely unexplored. Here we leverage Oxford Nanopore Technologies native RNA sequencing (dRNA), as well as ribosome profiling data, to uncover the full range of polyadenylated transcripts and translated open reading frames.
View Article and Find Full Text PDFLigand-dependent corepressor (LCOR) mediates normal and malignant breast stem cell differentiation. Cancer stem cells (CSCs) generate phenotypic heterogeneity and drive therapy resistance, yet their role in immunotherapy is poorly understood. Here we show that immune-checkpoint blockade (ICB) therapy selects for LCOR CSCs with reduced antigen processing/presentation machinery (APM) driving immune escape and ICB resistance in triple-negative breast cancer (TNBC).
View Article and Find Full Text PDFBiochim Biophys Acta Gene Regul Mech
June 2021
Background: RNA interference (RNAi) is a cellular mechanism used to fight various threats, including transposons, aberrant RNAs, and some types of viruses. This mechanism relies on the detection of dsRNA molecules, which through a pathway involving Dicer-2 (Dcr-2) and Argonaute 2 (AGO2), produces small interfering RNAs (siRNAs) that bind to the complementary RNAs triggering their degradation.
Methods: Using the cockroach Blattella germanica as a model, we examined AGO2 activity by depleting its mRNA using RNAi and analyzing the phenotypes produced.
The influence of DNA methylation on gene behavior and its consequent phenotypic effects appear to be very important, but the details are not well understood. Insects offer a diversity of DNA methylation modes, making them an excellent lineage for comparative analyses. However, functional studies have tended to focus on quite specialized holometabolan species, such as wasps, bees, beetles, and flies.
View Article and Find Full Text PDFScope: The effect of chronic supplementation with simple-sugar solutions on leptin signaling in liver, hypothalamus, and visceral white adipose tissue (vWAT) is studied, which is designed to mimic the temporal pattern of consumption by humans.
Methods And Results: Solutions of fructose or glucose are isocalorically supplemented (7 months) in female Sprague-Dawley rats consuming ad libitum rodent chow. After sacrifice, plasma and tissue samples (liver, hypothalamus, and vWAT) are collected.
A high consumption of fat and simple sugars, especially fructose, has been related to the development of insulin resistance, but the mechanisms involved in the effects of these nutrients are not fully understood. This study investigates the effects of a Western-type diet and liquid fructose supplementation, alone and combined, on insulin signalling and inflammation in low-density lipoprotein (LDL) receptor-deficient mice (LDL-R). LDL-R mice were fed chow or Western diet ±15% fructose solution for 12 weeks.
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