In addition to causing cold and flu-like symptoms, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can also cause chronic longer-term diseases. Antiviral drugs, especially used combinatorially, have the potential to reduce the severity of individual infections and prevent the development of chronic disease. One of the safest and most versatile reverse genetics systems for SARS-CoV-2 studies is a bacterial artificial chromosome (BAC)-based system harboring the WA1 strain full-length genome and attenuating deletions in the accessory open reading frame 3a and 7b proteins (ORF3a and ORF7b, respectively). Here, a scarless genome engineering technique called En Passant mutagenesis was used to change one amino acid in the viral main protease (Mpro P132) into the residue present in contemporary Omicron strains (H132), in order to more accurately study protease inhibitors and resistance mechanisms. This recombinant, attenuated viral system yields antiviral EC50 values for the active component of approved drugs including nirmatrelvir (Paxlovid) and ensitrelvir (Xocova) and, importantly, also enables a parallel assessment of drug efflux. For instance, the antiviral potency of nirmatrelvir improves 50-fold by inhibiting the P-Glycoprotein (P-Gp) transporter with ritonavir or tariquidar, whereas the potency of ensitrelvir is unaffected. This system also enables the safe isolation and characterization of viral variants with reduced sensitivity to drugs, as evidenced by Mpro M49L compromising the efficacy of ensitrelvir. Together, these systems combine to provide safe, reliable, and quantitative approaches for Mpro variant analysis and drug testing without the biosafety concerns of conducting these experiments using wildtype isolates. IMPORTANCE Safe genetic systems for studying coronavirus biology and developing next generation antivirals are important. One of the most versatile systems leverages a bacterial artificial chromosome to efficiently propagate and engineer a full-length SARS-CoV-2 genome. This system is also safe because it has crippling deletion mutations that limit virus replication to a small number of cell lines. Here, we use a genome engineering technology to change a single amino acid in the viruses’ main protease enzyme to match that of circulating Omicron isolates. The resulting attenuated virus was also used to demonstrate antiviral efficacy of approved drugs and uncover mutants with reduced drug sensitivity. The emergent mutants match those in a subset of circulating strains further demonstrating broad relevance.
This study constructed a pH-responsive P-TN/SF@Fe-Cur composite coating that demonstrated significant anti-infective, anti-inflammatory, antioxidant, pro-angiogenic, and pro-osteogenic effects in rat subcutaneous infection and femoral defect models.
ProteinReasoner is developed, a multimodal generative protein foundation model that sequentially connects amino acid sequence, evolutionary constraints and three-dimensional structure within a shared autoregressive architecture and suggests a general route towards reasoning across interdependent representations in other scientific domains.
Chaozhong Liu, Linlin Chao, Shaomin Ji et al.· bioRxiv· 1 citation
Due to its importance and wide adoption, wheat cultivation is promptly required to shift towards sustainable practices, reducing the dependency on chemical components. Among bio-based solutions aimed at securing the sustainability of wheat cultivation, biostimulants offer a versatile platform of eco-friendly tools assuring sustainability and profitability. Microalgae present a concrete example of a biostimulant source due to their richness in metabolites and high value products. Therefore, this study evaluated the biostimulant potential of eleven eco-extracts prepared from soil-isolated microalgae strains. Eco-extracts applied via soil drench at low dose (0.1 g/L) were investigated for their biostimulant effects on wheat growth, physiology, yield, and quality under controlled conditions. Results demonstrated significant ameliorations in treated plants as compared to the control, with no phytoinhibitory effects. Remarkable enhancements were notable in growth parameters such as shoot and root lengths (+40-70%), physiological traits such as total chlorophyll and stomatal conductance (+7-52%), yield components in the example of grain number per spike and thousand grain weight (+17-103%), and grain quality namely protein and polyphenol content (+2-fold to 4-fold). Similarly, phosphorus accumulation and uptake were significantly improved, while soil physicochemical status was ameliorated, indicating enhanced fertility. Multivariate analysis and composite index ranking marked Chlorella sp. GA18, Chlorella sp. GA65, Scenedesmus sp. GA69, and Chlorococcum sp. GA63 as eco-extracts with consistent performances across all plant traits. These findings highlighted the promising potential of integrating microalgae-based eco-friendly extracts in sustainable wheat cultivation.
Amer Chabili, Z. Hakkoum, F. Minaoui et al.· Plant Science· 1 citation
HydroGym is introduced, a solver-independent reinforcement learning platform providing more than 60 validated, openly available flow control environments spanning from canonical laminar flows to complex turbulent flows, with systematic progression in the Reynolds number up to Re = 4 × 105, and Mach number variations in two and three dimensions.
Christian Lagemann, Sajeda Mokbel, Miro Gondrum et al.· Nature· 1 citation
ABSTRACT Microplastics (MPs) accumulation in ecosystem and human organs poses urgent environmental and health risks, yet few enzymes efficiently degrade polyethylene terephthalate (PET) under physiological conditions. We leveraged deep learning to mine unexplored sequence space across 246 million proteins, discovering AhPETase, an evolutionarily distinct hydrolase with low homology (<50% sequence identity) to known PET‐degrading enzymes. This noncanonical biocatalyst efficiently depolymerizes PET at 37°C, outperforming all typical PETases and achieving a 7.76‐fold enhancement over IsPETase, one of the most representative mesophilic PETases. Additionally, engineered variant AhPETaseM1 retains functional activity for over 20 days under physiological conditions and can degrade post‐consumer PET MPs 34‐fold faster than recombinant human‐derived enzyme MG8 (rMG8) under equal enzyme loading. Critically, it reversed PET‐induced toxicity in human lung and colon cells, establishing the first proof‐of‐concept for enzymatic MPs detoxification.
Yuxuan Wang, Shijie He, Yuheng Chang et al.· Advancement of science· 0 citations
Missense pathogenicity predictors are routinely benchmarked against ClinVar, whose labels are strongly structured by gene: genes under diagnostic scrutiny accumulate pathogenic submissions while incidentally sequenced genes accumulate benign ones. We asked how much of a benchmark score this structure alone can produce. On 197,904 ClinVar missense variants validated against UniProt canonical sequences, a null model using no variant-level information, scoring each variant only by the pathogenic fraction of its own gene, reaches an area under the receiver operating characteristic curve (AUROC) of 0.921 under a random 10-fold split. On a common intersection of 169,989 variants, four current predictors exceed it by only 0.036 to 0.044. The inflation is not uniform, so it does not cancel when predictors are compared: under within-gene evaluation the ranking inverts, AlphaMissense rising from third to first and gMVP falling to third (p < 0.0001). The inversion survives removal of ceiling genes and replicates on an independently curated benchmark. Because both rankings derive from the same ClinVar labels, we arbitrated between them using data with no gene-level structure: agreement with 47 human deep mutational scanning assays matches the within-gene ranking and inverts the conventional one (p = 0.027, 0.0023). Across twenty-two dbNSFP predictors scored on one common intersection of 112,248 variants, with each tool’s exposure to clinical labels registered before any score was extracted, predictors never trained on such labels sit 0.051 AUROC behind supervised ones globally but only 0.026 behind within genes (difference +0.025 [+0.023, +0.027], p < 0.0001). Leave-one-out correction, the standard remedy, is worth 0.002 AUROC. Much of ClinVar benchmark performance reflects gene identity rather than variant effect, and the distortion changes which predictor a benchmark ranks first, in a direction experimental data contradicts. We release genenull, a single-file implementation, so reporting this baseline costs one function call. Author summary When a computer program predicts whether a genetic variant causes disease, we judge it by testing it against ClinVar, a public archive of variants clinicians have already interpreted. We found that this test is easier to pass than it looks. Some genes appear in ClinVar because they are suspected of causing disease, so most of their recorded variants are harmful; others are sequenced incidentally, so most of theirs are harmless. A program that knows nothing about a variant except which gene it sits in can exploit that pattern, and scores almost as well as the best tools available. This matters beyond a single number. When we removed the gene pattern and ranked variants inside a single gene, the order changed: the tool that looked best became worst, and the one that looked worst became best. Laboratory experiments that measure the effect of every possible variant in a protein agree with the new order, not the old one. Across twenty-two prediction tools, about half the advantage held by programs trained on clinical data disappears once the gene pattern is removed. We release software so anyone can measure this baseline in one line of code.
Saad Harrizi, I. Nait Irahal, Kabine Mostafa et al.· bioRxiv· 0 citations