Codon optimality, bias and usage in translation and mRNA decay

Genetic characterization of four bacteriophages of Salmonella enterica derived from different geographic regions in China via genomic comparison

Based on the AT content > GC content in four Salmonella enterica lytic bacteriophage genomes, information entropy analysis revealed that overall nucleotide usage bias is shaped in the gene population. This genetic feature directly contributes to synonymous codons tending toward the A/T end rather than the C/G end. Furthermore, the interplay between the nucleotide composition constraint from the bacteriophage itself and the natural selection caused by outside environments forces our bacteriophages into similar evolutionary trends in terms of overall codon usage patterns. We identified the nucleotide composition constraint which plays an important role in shaping synonymous codon usage patterns including the keto skew at the first codon position, the pyrimidine skew at the second position and the AT skew at the third position. Although the four bacteriophages were isolated from different geographical regions in China, they display similar evolutionary trends in terms of genomic organization and synonymous codon usage, which are strongly influenced by the nucleotide composition constraint of the bacteriophage. The findings of the present study reveal important details of the evolutionary and host-pathogen interactions of Salmonella enterica, which will benefit the efficient utilization of phages for therapeutic and other applications.

The complete mitochondrial genome of Sinojackia microcarpa: evolutionary insights and gene transfer

BACKGROUND

As a dicotyledonous plant within the Styracaceae family, Sinojackia microcarpa (S. microcarpa) is notable for its library-shaped fruit and sparse distribution, serving as a model system for studying the entire tree family. However, the scarcity of genomic data, particularly concerning the mitochondrial and nuclear sequences of S. microcarpa, has substantially impeded our understanding of its evolutionary traits and fundamental biological mechanisms.

RESULTS

This study presents the first complete mitochondrial genome sequence of S. microcarpa and conducts a comparative analysis of its protein-encoding genes across eight plant species. Our analysis revealed that the mitochondrial genome of S. microcarpa spans 687,378 base pairs and contains a total of 59 genes, which include 37 protein-coding genes (PCGs), 20 transfer RNA (tRNA) genes, and 2 ribosomal RNA (rRNA) genes. Sixteen plastid-derived fragments strongly linked with mitochondrial genes, including one intact plastid-related gene (rps7), were identified. Additionally, Ka/Ks ratio analysis revealed that most mitochondrial genes are under purifying selection, with a few genes, such as nad9 and ccmB, showing signs of relaxed or adaptive evolution. An analysis of twenty-nine protein-coding genes from twenty-four plant species reveals that S. microcarpa exhibits a closer evolutionary relationship with species belonging to the genus Camellia. The findings of this study provide new genomic data that enhance our understanding of S. microcarpa, and reveal its mitochondrial genome's evolutionary proximity to other dicotyledonous species.

CONCLUSIONS

Overall, this research enhances our understanding of the evolutionary and comparative genomics of S. microcarpa and other plants in the Styracaceae family and lays the foundation for future genetic studies and evolutionary analyses in the Styracaceae family.

RNA therapeutics in cardiovascular medicine

PURPOSE OF REVIEW

RNA therapeutics came to global attention when mRNA-based vaccines provided an answer to the SARS-CoV-2 pandemic. The immense significance of this development notwithstanding, it is important to note that almost a decade prior to the pandemic, RNA drugs had made important inroads toward the amelioration of disease. The first class of RNA therapies to be introduced into clinical use were the antisense oligomers and siRNA drugs which generally induce a therapeutic effect by acting to brake or to modulate mRNA expression. RNA therapeutics is quickly becoming the fourth pillar of pharmacotherapy, and will have broad applications, including for the treatment of cardiovascular disease.

RECENT FINDINGS

The United States (US) Food and Drug Administration (FDA) has approved several antisense oligomers (ASOs) and siRNA-based drugs to treat disorders associated with cardiovascular disease. In addition, multiple RNA-based drugs are in clinical trials to assess their safety and efficacy in patients with cardiovascular disorders, such as Zodasiran, a siRNA therapy that targets angiopoietin-like protein 3 (ANGPTL3) to reduce LDL cholesterol.

SUMMARY

Because of limitless sequence choice; speed of design; and relative ease of synthesis, RNA drugs will be rapidly developed, will have broad applications, and will be generated at lower cost than other drug types. This review aims to highlight RNA therapies for cardiovascular diseases that are approved, and those that are under clinical evaluation.

Loss of Nup160 dysregulates Cdc42 in the podocytes of podocyte-specific Nup160 knockout mice

Mutations in four genes encoding the outer ring complex of nuclear pore complexes (NPCs), NUP85, NUP107, NUP133 and NUP160, cause monogenic steroid-resistant nephrotic syndrome (SRNS). Knockout of NUP85, NUP107, or NUP133 in immortalized human podocytes activates CDC42, an important effector of SRNS pathogenesis. However, it is unknown whether or not loss of NUP160 dysregulates CDC42 in the podocytes. Here, we generated a podocyte-specific Nup160 knockout mouse model with double-fluorescent (mT/mG) Cre reporter genes using CRISPR/Cas9 and Cre/loxP technologies. We investigated nephrotic syndrome-associated phenotypes in the Nup160podo-/- mice, and performed single-cell transcriptomic and proteomic analysis of glomerular suspension cells and cultured primary podocytes, respectively. The Nup160podo-/- mice exhibited progressive proteinuria and fusion of podocyte foot processes. We found decreased Cdc42 protein and normal Cdc42 transcriptional level in the podocytes of the Nup160podo-/- mice using analysis of single-cell transcriptomes and proteomes. We subsequently observed that Cdc42 protein decreased in both kidney tissues and cultured primary podocytes of the Nup160podo-/- mice, although Cdc42 mRNA levels were elevated in the cultured primary podocytes of the Nup160podo-/- mice. We also found that Cdc42 activity was significantly reduced in the cultured primary podocytes of the Nup160podo-/- mice. In conclusion, loss of Nup160 dysregulated Cdc42 in the podocytes of the Nup160podo-/- mice with proteinuria and fusion of podocyte foot processes. Our findings suggest that the dysregulation of CDC42 may contribute to the pathogenesis of SRNS in patients with mutations in NUP160.

N-acetyltransferase 10 promotes glioblastoma malignancy via mRNA stabilization of Jumonji and AT-rich interaction domain containing 2

Glioblastoma (GBM) is the most common and aggressive form of malignant brain cancer, with a poor prognosis and a five-year survival rate of approximately 15%. The malignancy of GBM, including its treatment resistance and high recurrence rate, is largely attributed to the presence of cancer stem cells. Recent studies have identified the N-acetyltransferase 10 (NAT10), an enzyme responsible for catalyzing N4-acetylcytidine (ac4C) modification in RNA, as a key factor in cancer biology, with diverse roles across multiple cancer types. However, the specific contribution of this RNA modification to the malignancy of GBM remains unexplored. Here, we demonstrate that NAT10 expression is associated with poor prognosis in GBM patients and that NAT10 promotes GBM malignancy by enhancing stemness properties in human GBM cell line U251 and A172. A search for the underlying mechanism of NAT10-mediated enhancement of GBM stemness led to identification of polycomb repressive complex 2 (PRC2)-related genes as an epigenetic regulator. NAT10 mediates the acetylation of the coding region of Jumonji and AT-rich Interaction Domain containing 2 (JARID2) mRNA, which results in increased mRNA stability and elevated protein levels. Notably, knockdown of JARID2 significantly reduced GBM stemness, suppressed tumor growth, and extended the survival of xenograft mice. Our findings suggest that NAT10-mediated acetylation of JARID2 mRNA up-regulates its protein levels, thereby promoting stemness and contributing to the malignancy of GBM. Targeting this NAT10-JARID2 axis may represent a novel therapeutic approach for treatment of GBM.

A tripartite cell-free translation system to study mammalian translation

Genetic manipulation of cellular systems often leads to the adaptation of gene expression programs, rendering detailed mechanistic insights challenging to isolate and elucidate. The proteome constitutes the ultimate manifestation of gene expression programs with multiple layers of regulation to ensure faithful execution. While current high-throughput techniques to investigate regulation at the level of translation, such as Ribo-Seq and nascent proteomics, can capture nuanced changes in the translational landscape, they suffer from potential confounding factors imposed by adaptation of the cellular states. Cell-free translation systems have been used to elucidate molecular mechanisms for decades, but experimental setups have rigid composition and often rely on non-human model systems and artificially designed mRNA constructs. Here we detail a tripartite cell-free translation system based on the separation of mRNAs, ribosomes and ribosome-depleted cytoplasmic lysate from human cells, allowing for flexible reconstitution of translation reactions, which can be performed in 1-4 days. In this setup, cellular parts such as the cytoplasmic lysate can be kept constant, while ribosome complexes or mRNA can be varied or subjected to treatments or vice versa. We detail how complete mRNA populations can be used as input with subsequent detection of nascent peptides using autoradiography or mass spectrometry. We utilize this protocol to resolve which aspects of the translational machinery are selectively affected by environmental and cellular stress conditions that trigger ribosome stalling and collisions, which have been unresolvable until now.

Non-Viral RNA Therapies for Non-Small Cell Lung Cancer and Their Corresponding Clinical Trials

Ribonucleic acid (RNA)-based therapies represent a promising class of drugs for the treatment of non-small cell lung cancer (NSCLC) due to their ability to modulate gene expression. Therapies leveraging small interfering RNA (siRNA), messenger RNA (mRNA), microRNA (miRNA), and antisense oligonucleotides (ASOs) offer various advantages over conventional treatments, including the ability to target specific genetic mutations and the potential for personalized medicine approaches. However, the clinical translation of these therapeutics for the treatment of NSCLC faces challenges in delivery due to their immunogenicity, negative charge, and large size, which can be mitigated with delivery platforms. In this review, we provide a description of the pathophysiology of NSCLC and an overview of RNA-based therapeutics, specifically highlighting their potential application in the treatment of NSCLC. We discuss relevant classes of RNA and their therapeutic potential for NSCLC. We then discuss challenges in delivery and non-viral delivery strategies such as lipid- and polymer-based nanoparticles that have been developed to address these issues in preclinical models. Furthermore, we provide a summary table of clinical trials that leverage RNA therapies for NSCLC [which includes their National Clinical Trial (NCT) numbers] to highlight the current progress in NSCLC. We also discuss how these NSCLC therapies can be integrated with existing treatment modalities to enhance their efficacy and improve patient outcomes. Overall, we aim to highlight non-viral strategies that tackle RNA delivery challenges while showcasing RNA's potential as a next-generation therapy for NSCLC treatment.

The whole and its parts: cell-specific functions of brassinosteroids

Brassinosteroid (BR) phytohormones operate at both the cellular and organ levels, and impart distinct transcriptional responses in different cell types and developmental zones, with distinct effects on organ size and shape. Here, we review recent advances implementing high-resolution and modeling tools that have provided new insights into the role of BR signaling in growth coordination across cell layers. We discuss recently gained knowledge on BR movement and its relevance for intercellular communication, as well as how local protein environments enable cell- and stage-specific BR regulation. We also explore how tissue-specific alterations in BR signaling enhance crop yield. Together, we offer a comprehensive view of how BR signaling shapes the whole (overall growth dynamics) through its parts (intricate cellular interactions).

Systematic revelation and meditation on the significance of long exons using representative eukaryotic genomes

BACKGROUND

Long exons/introns are not evenly distributed in the genome, but the biological significance of this phenomenon remains elusive.

MATERIALS AND METHODS

Exon properties were analyzed in seven well-annotated reference genomes, including human and other representative model organisms: mouse, fruitfly, worm, mouse-ear cress, corn, and rice.

RESULTS

In all species, last exons in genes tend to be the longest. Additionally, we found that (1) canonical splicing motifs are strongly underrepresented in 3'UTR; (2) Last exons tend to have low GC content; (3) Comparing with other species, first exons in D. melanogaster genes demonstrate lower GC content than internal exons.

CONCLUSIONS

It cannot be excluded that last exons of genes exert essential regulatory roles and is subjected to natural selection, exhibiting differential splicing tendency, and GC content compared to other parts of the gene body.

The differential effect of SARS-CoV-2 NSP1 on mRNA translation and stability reveals new insights linking ribosome recruitment, codon usage, and virus evolution

The nonstructural protein 1 (NSP1) of SARS-CoV-2 blocks the messenger RNA (mRNA) entry channel of the 40S ribosomal subunit, causing inhibition of translation initiation and subsequent degradation of host mRNAs. However, target mRNA specificity and how viral mRNAs escape NSP1-mediated degradation have not been clarified to date. Here we found that NSP1 acts as a translational switch capable of blocking or enhancing translation depending on how preinitiation complex, 43S-PIC, is recruited to the mRNA, whereas NSP1-mediated mRNA degradation mostly depends on codon usage bias. Thus, fast-translating mRNAs with optimal codon usage for human cells that preferentially recruit 43S-PIC by threading showed a dramatic sensitivity to NSP1. Translation of SARS-CoV-2 mRNAs escapes NSP1-mediated inhibition by a proper combination of suboptimal codon usage and slotting-prone 5' UTR. Thus, the prevalence of nonoptimal codons found in SARS-CoV-2 and other coronavirus genomes is favored by the distinctive effect that NSP1 plays on translation and mRNA stability.

A deep learning model trained on expressed transcripts across different tissue types reveals cell-type codon-optimization preferences

Species-specific differences in protein translation can affect the design of protein-based drugs. Consequently, efficient expression of recombinant proteins often requires codon optimization. Publicly available optimization tools do not always result in higher expression levels and can lead to protein misfolding and reduced expression. Here, we aimed to develop a novel deep learning (DL) tool using a recurrent neural network (RNN) to define cell type-dependent codon biases. Using gene expression data from three different tissue types (brain, liver, and muscle) and all secretory genes, we trained DL models to predict optimal codon usage. Codon-optimized sequences for test reporter genes exhibited enhanced protein expression compared to their original sequences and those optimized using a publicly available tool. Interestingly, DL models trained on genes expressed in liver cells (hepatocytes) resulted in the highest levels of expression when tested in vitro, irrespective of the cell type. Our findings also demonstrate that DL-based codon optimization algorithms can significantly enhance protein translation, particularly for secretory proteins, which are crucial for therapeutic applications. This research represents a novel approach to codon optimization with broader implications for protein-based pharmaceuticals, vaccine manufacturing, gene therapy, and other recombinant DNA products.

Modifications of RNA in cancer: a comprehensive review

RNA modifications play essential roles in post-transcriptional gene regulation and have emerged as significant contributors to cancer biology. Major chemical modifications of RNA include N6-methyladenosine (m6A), 5-methylcytosine (m5C), N1-methyladenosine (m1A), pseudouridine (ψ), and N7-methylguanosine (m7G). Their dynamic regulation highlights their roles in gene expression modulation, RNA stability, and translation. Advanced high-throughput detection methods, ranging from liquid chromatography-mass spectrometry and high-performance liquid chromatography to next-generation sequencing (NGS) and nanopore direct RNA sequencing, have enabled detailed studies of RNA modifications in cancer cells. Aberrant RNA modifications are associated with the dysregulation of tumor suppressor genes and oncogenes, influencing cancer progression, therapy resistance, and immune evasion. Emerging research suggests the therapeutic potential of targeting RNA-modifying enzymes and their inhibitors in cancer treatment. This review compiles and analyzes the latest findings on RNA modifications, presenting an in-depth discussion of the diverse chemical alterations that occur in RNA and their profound implications in cancer biology. It integrates fundamental principles with cutting-edge research, offering a holistic perspective on how RNA modifications influence gene expression, tumor progression, and therapeutic resistance. It emphasizes the need for further studies to elucidate the complex roles of RNA modifications in cancer, as well as the potential for multimodality therapeutic strategies that exploit the dynamic and reversible nature of these epitranscriptomic marks. It also attempts to highlight the challenges, gaps, and limitations of RNA modifications in cancer that should be tackled before their functional implications. Understanding the interplay between RNA modifications, cancer pathways, and their inhibitors will be crucial for developing promising RNA-based therapeutic approaches to cancer and personalized medicine strategies.

Influence of Nucleophosmin (NPM1) Genotypes on Outcome of Patients With AML: An AIEOP-BFM and COG-SWOG Intergroup Collaboration

PURPOSE

Several genomic subsets of NPM1 mutations with varying sequences (type A, B, D, etc) have been identified. Despite molecular heterogeneity, NPM1 mutations cumulatively portend a more favorable outcome, but biology and prognostic implications of different genomic subsets have not been extensively studied. In this multicentric study, we investigated the impact of NPM1 genotypes on patient's outcomes and interrogated the underlying biology of the different subtypes.

MATERIALS AND METHODS

Of more than 4,000 patients enrolled in multiple pediatric cooperative (AIEOP, BFM, ELAM02, NOPHO, DCOG, and COG trials), or adult (SWOG) trials, 348 pediatric and 75 adult AML patients with known NPM1 genotype and available outcome were selected for this study. Diverse NPM1 variants were correlated with the probabilities of overall survival (OS) and event-free survival. Nuclear localization and translational efficiency of the NPM1 variants was studied.

RESULTS

Evaluation of clinical outcome on the basis of NPM1 genotypes showed that patients with type A, B, and other rare variants had similarly favorable outcomes, whereas those with type D had a significantly worse outcome (OS of 63% for type D v 86% for type non-D, P = .005). Multivariate analysis confirmed type D as an independent prognostic factor associated with inferior OS (hazard ratio, 3; P = .005). In vitro, we demonstrated that in type D versus type A synonymous variants, codon optimality plays major roles in determining gene expression levels, and translation efficiency, which resulted in a more expressed NPM1-D mRNA and protein, mediating peculiar mitochondrial gene expression.

CONCLUSION

The evaluation of specific NPM1 genotypes identified AML patients with type D mutations being significantly associated with inferior outcomes, suggesting a reclassification of D cases to higher-risk groups.

The Relationship Between Ribosome-Associated Quality Control and Neurological Disorders

Ribosome-associated quality control (RQC), a ubiquitous process essential for maintaining protein homeostasis in eukaryotes, acts as a critical surveillance system for protein translation. By identifying and eliminating stalled ribosomes, RQC prevents aberrant translation and the production of potentially toxic misfolded proteins. The review focuses on the role of RQC in mammals, where its complete functionality remains to be elucidated. This study delves into the mechanisms through which dysfunction in RQC plays a role in the development of neurological disorders, focusing on neurodegenerative and neurodevelopmental diseases. We explore the underlying mechanisms by which RQC dysfunction contributes to the pathogenesis of neurological disorders, particularly neurodegenerative and neurodevelopmental diseases. Further research is crucial to unravel the intricate mechanisms governing RQC's influence on neurological function. This knowledge will pave the way for exploring therapeutic avenues targeting RQC factors as potential interventions for these debilitating diseases. By shedding light on RQC's contribution to neurological disorders, this review opens doors for developing targeted therapies and interventions.

Less is more: slow-codon windows enhance eGFP mRNA resilience against RNA interference

Extensive efforts have been devoted to enhancing the translation efficiency of mRNA delivered to mammalian cells via codon optimization. However, the impact of codon choice on mRNA stability remains underexplored. In this study, we investigated the influence of codon usage on mRNA degradation kinetics in cultured human cell lines using live-cell imaging on single-cell arrays. By measuring mRNA lifetimes at the single-cell level for synthetic mRNA constructs, we confirmed that mRNAs containing slowly translated codon windows have shorter lifetimes. Unexpectedly, these mRNAs did not exhibit decreased stability in the presence of small interfering RNA (siRNA) compared with the unmutated sequence, suggesting an interference of different concurrent degradation mechanisms. We employed stochastic simulations to predict ribosome density along the open reading frame, revealing that the ribosome densities correlated with mRNA stability in a cell-type- and codon-position-specific manner. In summary, our results suggest that the effect of codon choice and its influence on mRNA lifetime is context-dependent with respect to cell type, codon position and RNA interference.

Overproduction and Characterization of Recombinant Soluble Trypanosoma brucei Phospholipase A2

Trypanosoma brucei phospholipase A2 (TbPLA2) is a validated drug target but the difficulty in expressing its soluble recombinant protein has limited its exploitation for drug and vaccine development for African and American trypanosomiases. We utilized recombinant deoxyribonucleic acid (DNA) technology approaches to express soluble TbPLA2 in Escherichia coli and Pichia pastoris and biochemically characterize the purified enzyme. Full-length TbPLA2 was insoluble and deposited as inclusion bodies when expressed in E. coli. However, soluble and active forms were obtained when both the full-length and truncated TbPLA2 were expressed in fusion with N-terminal FLAG tag and C-terminal eGFP in P. pastoris, and the truncated protein in fusion with N-terminal FLAG tag and C-terminal mClover in E. coli. Truncated TbPLA2 lacking the signal peptide and transmembrane domain was finally expressed in Rosetta 2 cells and purified to homogeneity. Its migration on sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) confirmed its size to be 39 kDa. Kinetic studies revealed that the enzyme has a specific activity of 107.14 µmol/min/mg, a V max of 25.1 µmol/min, and a K M of 1.58 mM. This is the first report on the successful expression of soluble and active recombinant TbPLA2, which will facilitate the discovery of its specific inhibitors for the development of therapeutics for trypanosomiasis.

Role of nucleotide pair frequency and synonymous codon usage in the evolution of bovine viral diarrhea virus

Synonymous codon usage plays an important role in the adaptation of viruses to their hosts. Bovine viral diarrhea virus (BVDV) relies on a high mutation rate in its genome to achieve the necessary fitness in a particular host. However, the question of which selective forces influence nucleotide pair and synonymous codon usage patterns in different BVDV genotypes remains unresolved. Here, 169 BVDV strains isolated at different times in various countries were analyzed to compare their dinucleotide frequency and synonymous codon usage. Examination of the nucleotide usage pattern in the open reading frame (ORF) of BVDV revealed a significantly higher frequency of purine than pyrimidine, with the highest extent of nucleotide usage bias observed in the first codon position. Moreover, a nucleotide pair bias, especially favoring CpG dinucleotides, was observed in all of the genotypes. Together, the nucleotide composition constraints and nucleotide pair bias appear to have influenced the overall codon usage pattern. Nucleotide pair and synonymous codon usage biases were associated with individual genotypes to different degrees. Of particular note, BVDV-1 exhibited more variation in its nucleotide pair and synonymous codon usage than BVDV-2 and BVDV-3, suggesting that these patterns are shaped both by selection of mutations in the viral genome and translational selection in the host.

Inferring protein from transcript abundances using convolutional neural networks

BACKGROUND

Although transcript abundance is often used as a proxy for protein abundance, it is an unreliable predictor. As proteins execute biological functions and their expression levels influence phenotypic outcomes, we developed a convolutional neural network (CNN) to predict protein abundances from mRNA abundances, protein sequence, and mRNA sequence in Homo sapiens (H. sapiens) and the reference plant Arabidopsis thaliana (A. thaliana).

RESULTS

After hyperparameter optimization and initial data exploration, we implemented distinct training modules for value-based and sequence-based data. By analyzing the learned weights, we revealed common and organism-specific sequence features that influence protein-to-mRNA ratios (PTRs), including known and putative sequence motifs. Adding condition-specific protein interaction information identified genes correlated with many PTRs but did not improve predictions, likely due to insufficient data. The integrated model predicted protein abundance on unseen genes with a coefficient of determination (r2) of 0.30 in H. sapiens and 0.32 in A. thaliana.

CONCLUSIONS

For H. sapiens, our model improves prediction performance by nearly 50% compared to previous sequence-based approaches, and for A. thaliana it represents the first model of its kind. The model's learned motifs recapitulate known regulatory elements, supporting its utility in systems-level and hypothesis-driven research approaches related to protein regulation.

Acetyltransferase NAT10 inhibits T-cell immunity and promotes nasopharyngeal carcinoma progression through DDX5/HMGB1 axis

BACKGROUND

Immunosuppression significantly contributes to treatment failure in nasopharyngeal carcinoma (NPC). Messenger RNA (mRNA) modifications such as methylation and acetylation play crucial roles in immunosuppression. However, N4-acetylcytidine (ac4C), the only acetylation modification event has rarely been studied in NPC.

METHODS

First, clinical tissue samples and nude mouse models were used to explore the expression of N-acetyltransferase 10 (NAT10) in NPC and its influence on it. Second, The Cancer Genome Atlas immune database and transgenic mouse peripheral blood immune cell panel were used to verify the immune cells mainly affected by NAT10. Then, NAT10 ac4C acetylation modification and expression of significantly upregulated transcription factors were explored by acetylated RNA immunoprecipitation sequence binding to RNA sequencing. Then, the downstream regulatory genes of CCAAT enhancer binding protein γ (CEBPG), dead box helicase 5 (DDX5) and helicase-like transcription factors (HLTF) were analyzed by luciferase report and chromatin Immunoprecipitation. Finally, the effect of inhibition of NAT10 on anti-programmed cell death protein 1 (PD-1) treatment sensitivity was verified by animal models.

RESULTS

In this study, we aimed to explore the role of NAT10, the enzyme responsible for ac4C modification, in NPC progression and patient prognosis. Elevated NAT10 promoted NPC progression and correlated with poor prognosis in patients with NPC. NAT10-mediated ac4C modification of CEBPG, DDX5, and HLTF mRNA improved their stability and translation efficiency, with the NAT10/ac4C/DDX5 axis upregulating high mobility group box 1 (HMGB1) and inhibiting CD4+ and CD8+ T cells. Inhibition of NAT10 increased the sensitivity to PD-1 therapy. Additionally, HLTF was found to transcriptionally regulate NAT10, indicating the formation of an HLTF-NAT10 positive feedback loop.

CONCLUSIONS

Our study elucidates the mechanism by which the NAT10/DDX5/HMGB1 axis promotes the immunosuppression of NPC by promoting T-cell dysfunction. In addition, NAT10 knockdown can enhance anti-PD-1 treatment sensitivity as a combination therapy for NPC.

The ribosome as a platform to coordinate mRNA decay

Messenger RNA (mRNA) homeostasis is a critical aspect of cellular function, involving the dynamic interplay between transcription and decay processes. Recent advances have revealed that the ribosome plays a central role in coordinating mRNA decay, challenging the traditional view that free mRNA is the primary substrate for degradation. This review examines the mechanisms whereby ribosomes facilitate both the licensing and execution of mRNA decay. This involves factors such as the Ccr4-Not complex, small MutS-related domain endonucleases, and various quality control pathways. We discuss how translational fidelity, as well as the presence of nonoptimal codons and ribosome collisions, can trigger decay pathways such as nonstop decay and no-go decay. Furthermore, we highlight the direct association of canonical exonucleases, such as Xrn1 and the Ski-exosome system, with the ribosome, underscoring the ribosome's multifaceted role as a platform for regulatory processes governing mRNA stability. By integrating recent findings, this review offers a comprehensive overview of the structural basis of how ribosomes not only facilitate translation but also serve as critical hubs for mRNA decay coordination.

Genes and Pathways Comprising the Human and Mouse ORFeomes Display Distinct Codon Bias Signatures that Can Regulate Protein Levels

Arginine, glutamic acid and selenocysteine based codon bias has been shown to regulate the translation of specific mRNAs for proteins that participate in stress responses, cell cycle and transcriptional regulation. Defining codon-bias in gene networks has the potential to identify other pathways under translational control. Here we have used computational methods to analyze the ORFeome of all unique human (19,711) and mouse (22,138) open-reading frames (ORFs) to characterize codon-usage and codon-bias in genes and biological processes. We show that ORFeome-wide clustering of gene-specific codon frequency data can be used to identify ontology-enriched biological processes and gene networks, with developmental and immunological programs well represented for both humans and mice. We developed codon over-use ontology mapping and hierarchical clustering to identify multi-codon bias signatures in human and mouse genes linked to signaling, development, mitochondria and metabolism, among others. The most distinct multi-codon bias signatures were identified in human genes linked to skin development and RNA metabolism, and in mouse genes linked to olfactory transduction and ribosome, highlighting species-specific pathways potentially regulated by translation. Extreme codon bias was identified in genes that included transcription factors and histone variants. We show that re-engineering extreme usage of C- or U-ending codons for aspartic acid, asparagine, histidine and tyrosine in the transcription factors CEBPB and MIER1, respectively, significantly regulates protein levels. Our study highlights that multi-codon bias signatures can be linked to specific biological pathways and that extreme codon bias with regulatory potential exists in transcription factors for immune response and development.

Regulation of sod1 mRNA and protein abundance by zinc in fission yeast is dependent on the CCR4-NOT complex

Zinc is an essential micronutrient that serves as a cofactor in a wide variety of enzymes, including Cu-Zn Superoxide Dismutase 1 (Sod1). We have discovered in Schizosaccharomyces pombe that Sod1 mRNA and protein levels are regulated in response to cellular zinc availability. We demonstrate that lower levels of sod1 mRNA and protein accumulate under low zinc conditions and that this regulation does not require the sod1 promoter or known factors that regulate the transcription of sod1 in response to zinc and other environmental stresses. Further analyses using yeast deletion strains and an inactive allele of Caf1 revealed that the reduced accumulation of sod1 mRNA and protein under low zinc conditions depends on the Caf1 and Ccr4 deadenylases of the CCR4-NOT complex. We also found that Caf1 and Ccr4 are both required for growth under zinc-limiting conditions. To gain additional mechanistic insight we used immunoblot analysis to map the regions required for the regulation of the Sod1 protein by zinc. We found that the sod1 ORF and 3'UTR are both necessary and sufficient for the zinc-dependent changes in Sod1 protein abundance. Our studies reveal a novel mechanism of altering mRNA and protein abundance in response to zinc status, which depends on the CCR4-NOT complex.

Biological function and mechanism of NAT10 in cancer

N-acetyltransferase 10 (NAT10) is a nucleolar acetyltransferase with an acetylation catalytic function and can bind various protein and RNA molecules. As the N4-acetylcytidine (ac4C) "writer" enzyme, NAT10 is reportedly involved in a variety of physiological and pathological activities. Currently, the NAT10-related molecular mechanisms in various cancers are not fully understood. In this review, we first describe the cellular localization of NAT10 and then summarize its numerous biological functions. NAT10 is involved in various biological processes by mediating the acetylation of different proteins and RNAs. These biological functions are also associated with cancer progression and patient prognosis. We also review the mechanisms by which NAT10 plays roles in various cancer types. NAT10 can affect tumor cell proliferation, metastasis, and stress tolerance through its acetyltransferase properties. Further research into NAT10 functions and expression regulation in tumors will help explore its future potential in cancer diagnosis, treatment, and prognosis.

The non-canonical nucleotides and prebiotic evolution

The mystery of the origin of life has been puzzling mankind for several millenia. Starting from the second half of the 20th century, when the crucial role of nucleic acids in biological heredity became apparent, the emphasis in the field has shifted to the explanation of the origin of nucleic acids and the mechanisms of copying of macromolecules. In the 1960s, the hypothesis of the RNA World was proposed, according to which the first stages of the origin of life on Earth were associated with the appearance of self-replicating complexes based on RNA, that were akin to RNA-enzymes that catalyze critical for life chemical reactions. Currently, it has been shown that different forms of RNA include not only canonical (adenine, uracil, guanine, cytosine), but also about 170 non-canonical nucleotides. In this review, we discuss potential roles of these non-canonical nucleotides in the processes of molecular prebiotic evolution, such as the emergence of canonical RNA nucleotides and catalytic RNAs, as well as the origin of template synthesis of RNA and proteins.

Nanocarrier-Mediated RNA Delivery Platform as a Frontier Strategy for Hepatic Disease Treatment: Challenges and Opportunities

Hepatic diseases cause serious public health problems worldwide, and there is an urgent need to develop effective therapeutic agents. In recent years, significant progress is made in RNA therapy, and RNA molecules, such as mRNAs, siRNAs, miRNAs, and RNA aptamers, are shown to provide significant advantages in the treatment of hepatic diseases. However, the drawbacks of RNAs, such as their poor biological stability, easy degradation by nucleases in vivo, low bioavailability, and low concentrations in target tissues, significantly limit the clinical application of RNA-based drugs. Therefore, exploring and developing effective nanoscale delivery platforms for RNA therapeutics are of immense value. This review focuses on the different types of hepatic diseases and RNA therapeutics, summarizing various nanoscale delivery platforms and their strengths and weaknesses. Finally, the current status and future prospects of nanoscale delivery systems for RNA therapy are discussed.

MicroRNA-regulated suppression of some overexpressed genes in schizophrenia and their evolutionary significance

Impaired formation of the brain or nervous system is the root cause of neurodevelopmental disorders which appear in pregnancy or soon after birth. One such neurodevelopmental disorder is Schizophrenia. Among the most serious forms of psychosis, Schizophrenia (SCZ) affects 1 % of the general population. MiRNA targeting sites and codon usage of nine overexpressed genes in Schizophrenia were investigated in this study. The neutrality plot demonstrated the importance of natural selection over mutational pressure in the evolution of these genes. The analysis of COSM revealed that the miRNA target regions of the genes were encoded by non-optimal codons, resulting in low translational efficiency, whereas the GC content revealed that the miRNA-mRNA binding was strong. From this study it was concluded that each overexpressed gene was targeted by several human miRNAs for putative suppression. These identified miRNAs could have therapeutic potential in Schizophrenia therapy.

Translation of the downstream ORF from bicistronic mRNAs by human cells: Impact of codon usage and splicing in the upstream ORF

Biochemistry textbooks describe eukaryotic mRNAs as monocistronic. However, increasing evidence reveals the widespread presence and translation of upstream open reading frames preceding the "main" ORF. DNA and RNA viruses infecting eukaryotes often produce polycistronic mRNAs and viruses have evolved multiple ways of manipulating the host's translation machinery. Here, we introduce an experimental model to study gene expression regulation from virus-like bicistronic mRNAs in human cells. The model consists of a short upstream ORF and a reporter downstream ORF encoding a fluorescent protein. We have engineered synonymous variants of the upstream ORF to explore large parameter space, including codon usage preferences, mRNA folding features, and splicing propensity. We show that human translation machinery can translate the downstream ORF from bicistronic mRNAs, albeit reporter protein levels are thousand times lower than those from the upstream ORF. Furthermore, synonymous recoding of the upstream ORF exclusively during elongation significantly influences its own translation efficiency, reveals cryptic splice signals, and modulates the probability of downstream ORF translation. Our results are consistent with a leaky scanning mechanism facilitating downstream ORF translation from bicistronic mRNAs in human cells, offering new insights into the role of upstream ORFs in translation regulation.

Comparative Transcriptomic Analysis Provides Insight into Spatiotemporal Expression Patterns of Pivotal Genes During Critical Growth Stages in Min Pig Breed

The growth and development of animals are dynamic processes characterized by fluctuations. Min pigs, a local breed renowned for their superior meat quality, present an intriguing yet poorly understood relationship between this quality and their growth and development patterns. To elucidate this relationship, we employed a multi-faceted approach that included comparative transcriptomics, quantitative real-time PCR (qRT-PCR), selection pressure analysis of key genes, and three-dimensional protein structure simulations. Our findings revealed that 150 days (150 d) of age represented a pivotal turning point in the growth and development of Min pigs. Thirteen key genes exhibiting significant differential expression between early and late growth stages were identified. Notably, the CDK2 gene demonstrated specific high expression in the hind limb muscles and adipose tissues during the later growth stages. Comparative analysis with the African warthog revealed that while the CDK2 protein structure remained conserved, base mutations in upstream and downstream non-coding regions resulted in strong positive selection pressure on the CDK2 gene. These results suggest that CDK2 plays a crucial role in defining the spatiotemporal characteristics of meat development during the domestication of Min pigs. This study provides critical insights into the growth and development patterns of domestic pigs and offers a robust scientific foundation for improving meat quality traits through domestication.

Codon usage analysis in selected virulence genes of Staphylococcal species

The Staphylococcus genus, composed of Gram-positive bacteria, includes several pathogenic species such as Staphylococcus aureus, S. epidermidis, S. haemolyticus, and S. saprophyticus, each implicated in a range of infections. This study investigates the codon usage patterns in key virulence genes, including Autolysin (alt), Elastin Binding protein (EbpS), Lipase, Thermonuclease, Intercellular Adhesion Protein (IcaR), and V8 Protease, across four Staphylococcus species. Using metrics such as the Effective Number of Codons (ENc), Relative Synonymous Codon Usage (RSCU), Codon Adaptation Index (CAI), alongside neutrality and parity plots, we explored the codon preferences and nucleotide composition biases. Our findings revealed a pronounced AT-rich codon preference, with AT-rich genomes likely aiding in energy-efficient translation and bacterial survival in host environments. These insights provide a deeper understanding of the evolutionary adaptations and translational efficiency mechanisms that contribute to the pathogenicity of Staphylococcus species. This knowledge could pave the way for novel therapeutic interventions targeting codon usage to disrupt virulence gene expression.

Advances in nucleic acid-based cancer vaccines

Nucleic acid vaccines have emerged as crucial advancements in vaccine technology, particularly highlighted by the global response to the COVID-19 pandemic. The widespread administration of mRNA vaccines against COVID-19 to billions globally marks a significant milestone. Furthermore, the approval of an mRNA vaccine for Respiratory Syncytial Virus (RSV) this year underscores the versatility of this technology. In oncology, the combination of mRNA vaccine encoding neoantigens and immune checkpoint inhibitors (ICIs) has shown remarkable efficacy in eliciting protective responses against diseases like melanoma and pancreatic cancer. Although the use of a COVID-19 DNA vaccine has been limited to India, the inherent stability at room temperature and cost-effectiveness of DNA vaccines present a viable option that could benefit developing countries. These advantages may help DNA vaccines address some of the challenges associated with mRNA vaccines. Currently, several trials are exploring the use of DNA-encoded neoantigens in combination with ICIs across various cancer types. These studies highlight the promising role of nucleic acid-based vaccines as the next generation of immunotherapeutic agents in cancer treatment. This review will delve into the recent advancements and current developmental status of both mRNA and DNA-based cancer vaccines.

Computational biology and artificial intelligence in mRNA vaccine design for cancer immunotherapy

Messenger RNA (mRNA) vaccines offer an adaptable and scalable platform for cancer immunotherapy, requiring optimal design to elicit a robust and targeted immune response. Recent advancements in bioinformatics and artificial intelligence (AI) have significantly enhanced the design, prediction, and optimization of mRNA vaccines. This paper reviews technologies that streamline mRNA vaccine development, from genomic sequencing to lipid nanoparticle (LNP) formulation. We discuss how accurate predictions of neoantigen structures guide the design of mRNA sequences that effectively target immune and cancer cells. Furthermore, we examine AI-driven approaches that optimize mRNA-LNP formulations, enhancing delivery and stability. These technological innovations not only improve vaccine design but also enhance pharmacokinetics and pharmacodynamics, offering promising avenues for personalized cancer immunotherapy.

Predicting the translation efficiency of messenger RNA in mammalian cells

The degree to which translational control is specified by mRNA sequence is poorly understood in mammalian cells. Here, we constructed and leveraged a compendium of 3,819 ribosomal profiling datasets, distilling them into a transcriptome-wide atlas of translation efficiency (TE) measurements encompassing >140 human and mouse cell types. We subsequently developed RiboNN, a multitask deep convolutional neural network, and classic machine learning models to predict TEs in hundreds of cell types from sequence-encoded mRNA features, achieving state-of-the-art performance (r=0.79 in human and r=0.78 in mouse for mean TE across cell types). While the majority of earlier models solely considered 5' UTR sequence1, RiboNN integrates contributions from the full-length mRNA sequence, learning that the 5' UTR, CDS, and 3' UTR respectively possess ~67%, 31%, and 2% per-nucleotide information density in the specification of mammalian TEs. Interpretation of RiboNN revealed that the spatial positioning of low-level di- and tri-nucleotide features (i.e., including codons) largely explain model performance, capturing mechanistic principles such as how ribosomal processivity and tRNA abundance control translational output. RiboNN is predictive of the translational behavior of base-modified therapeutic RNA, and can explain evolutionary selection pressures in human 5' UTRs. Finally, it detects a common language governing mRNA regulatory control and highlights the interconnectedness of mRNA translation, stability, and localization in mammalian organisms.

Mutability and hypermutation antagonize immunoglobulin codon optimality

The efficacy of antibody responses is inherently linked to paratope diversity, as generated through V(D)J recombination and somatic hypermutation. Despite this, it is unclear how genetic diversification mechanisms evolved alongside codon optimality and affect antibody expression. Here, we analyze germline immunoglobulin (IG) genes, natural V(D)J repertoires, serum IgG, and monoclonal antibody (mAb) expression through the lens of codon optimality. Germline variable genes (IGVs) exhibit diverse optimality that is inversely related to mutability. Hypermutation deoptimizes heavy-chain (IGH) VDJ repertoires within human tonsils, bone marrow, lymph nodes (including SARS-CoV-2-specific clones), blood (HIV-1-specific clones), mice, and zebrafish. Analyses of mutation-affected codons show that targeting to complementarity-determining regions constrains deoptimization. Germline IGHV optimality correlates with serum variable fragment (VH) usage after influenza vaccination, while synonymous deoptimization attenuated mAb yield. These findings provide unanticipated insights into an antagonistic relationship between diversification mechanisms and codon optimality. Ultimately, the need for diversity takes precedence over that for the most optimal codon usage.

Decoding Codon Bias: The Role of tRNA Modifications in Tissue-Specific Translation

The tRNA epitranscriptome has been recognized as an important player in mRNA translation regulation. Our knowledge of the role of the tRNA epitranscriptome in fine-tuning translation via codon decoding at tissue or cell levels remains incomplete. We analyzed tRNA expression and modifications as well as codon optimality across seven mouse tissues. Our analysis revealed distinct enrichment patterns of tRNA modifications in different tissues. Queuosine (Q) tRNA modification was most enriched in the brain compared to other tissues, while mitochondrial tRNA modifications and tRNA expression were highest in the heart. Using this observation, we synthesized, and delivered in vivo, codon-mutated EGFP for Q-codons, where the C-ending Q-codons were replaced with U-ending codons. The protein levels of mutant EGFP were downregulated in liver, which is poor in Q, while in brain EGFP, levels did not change. These data show that understanding tRNA modification enrichments across tissues is not only essential for understanding codon decoding and bias but can also be utilized for optimizing gene and mRNA therapeutics to be more tissue-, cell-, or condition-specific.

Conditional requirement for dimerization of the membrane-binding module for BTK signaling in lymphocyte cell lines

Bruton's tyrosine kinase (BTK) is a major drug target in immune cells. The membrane-binding pleckstrin homology and tec homology (PH-TH) domains of BTK are required for signaling. Dimerization of the PH-TH module strongly stimulates the kinase activity of BTK in vitro. Here, we investigated whether BTK dimerizes in cells using the PH-TH module and whether this dimerization is necessary for signaling. To address this question, we developed high-throughput mutagenesis assays for BTK function in Ramos B cells and Jurkat T cells. We measured the fitness costs for thousands of point mutations in the PH-TH module and kinase domain to assess whether dimerization of the PH-TH module and BTK kinase activity were necessary for function. In Ramos cells, we found that neither PH-TH dimerization nor kinase activity was required for BTK signaling. Instead, in Ramos cells, BTK signaling was enhanced by PH-TH module mutations that increased membrane adsorption, even at the cost of reduced PH-TH dimerization. In contrast, in Jurkat cells, we found that BTK signaling depended on both PH-TH dimerization and kinase activity. Evolutionary analysis indicated that BTK proteins in organisms that evolved before the divergence of ray-finned fishes lacked PH-TH dimerization but had active kinase domains, similar to other Tec family kinases. Thus, PH-TH dimerization is a distinct feature of BTK that evolved to exert stricter regulatory control on kinase activity as adaptive immune systems gained increased complexity.

ARI0003: Co-transduced CD19/BCMA dual-targeting CAR-T cells for the treatment of non-Hodgkin lymphoma

CD19 CAR-T therapy has achieved remarkable responses in relapsed/refractory non-Hodgkin lymphoma (NHL). However, challenges persist, with refractory responses or relapses after CAR-T administration linked to CD19 loss or downregulation. Given the co-expression of CD19 and BCMA in NHL, we hypothesized that dual targeting could enhance long-term efficacy. We optimized different dual-targeting approaches, including co-transduction of two lentiviral vectors, bicistronic, tandem, and loop and pool strategies, based on our academic anti-CD19 (ARI0001) and anti-BCMA (ARI0002h) CAR-T cells. Comparison with anti-CD19/CD20 or anti-CD19/CD22 dual targeting was also performed. We demonstrate that anti-CD19/BCMA CAR-T cells can be effectively generated through the co-transduction of two lentiviral vectors after optimization to minimize competition for cellular resources. Co-transduced T cells, called ARI0003, effectively targeted NHL tumor cells with high avidity, outperforming anti-CD19 CAR-T cells and other dual-targeting approaches both in vitro and in vivo, particularly in low CD19 antigen density models. ARI0003 maintained effectiveness post-CD19 CAR-T treatment in xenograft models and in spheroids from relapsed CART-treated patients. ARI0003 CAR-T cells were effectively manufactured under Good Manufacturing Practice conditions, with a reduced risk of genotoxicity compared to other dual-targeting approaches. A first-in-human phase 1 clinical trial (CARTD-BG-01; this study was registered at ClinicalTrials.gov [NCT06097455]) has been initiated to evaluate the safety and efficacy of ARI0003 in NHL.

Predicting gene sequences with AI to study codon usage patterns

Selective pressure acts on the codon use, optimizing multiple, overlapping signals that are only partially understood. We trained AI models to predict codons given their amino acid sequence in the eukaryotes Saccharomyces cerevisiae and Schizosaccharomyces pombe and the bacteria Escherichia coli and Bacillus subtilis to study the extent to which we can learn patterns in naturally occurring codons to improve predictions. We trained our models on a subset of the proteins and evaluated their predictions on large, separate sets of proteins of varying lengths and expression levels. Our models significantly outperformed naïve frequency-based approaches, demonstrating that there are learnable dependencies in evolutionary-selected codon usage. The prediction accuracy advantage of our models is greater for highly expressed genes and is greater in bacteria than eukaryotes, supporting the hypothesis that there is a monotonic relationship between selective pressure for complex codon patterns and effective population size. In S. cerevisiae and bacteria, our models were more accurate for longer proteins, suggesting that the learned patterns may be related to cotranslational folding. Gene functionality and conservation were also important determinants that affect the performance of our models. Finally, we showed that using information encoded in homologous proteins has only a minor effect on prediction accuracy, perhaps due to complex codon-usage codes in genes undergoing rapid evolution. Our study employing contemporary AI methods offers a unique perspective and a deep-learning-based prediction tool for evolutionary-selected codons. We hope that these can be useful to optimize codon usage in endogenous and heterologous proteins.

Detection of Nuclear RNA Decay Intermediates Using a Modified Oxford Nanopore RNA Sequencing Strategy

The nuclear RNA exosome complex is crucial for noncoding RNA processing and RNA quality control in the nucleus. Identifying substrates and intermediates of RNA decay pathways, such as those mediated by the exosome complex using Oxford Nanopore sequencing can be difficult in part because a simple method to detect them has been lacking and also because some of these RNAs lack abundant poly(A) tails which are required for Oxford Nanopore-based sequencing. Here we describe an Oxford nanopore-based approach which can be used to identify long reads corresponding to precursors and products of nuclear exosome processing. We are able to observe accumulation of unprocessed snoRNAs, cleavage products of the yeast nuclear RNase III endonuclease Rnt1p when the nuclear exosome component Rrp6p is inactivated.

Dynamic mRNA Stability Buffer Transcriptional Activation During Neuronal Differentiation and Is Regulated by SAMD4A

Neurons are exceptionally sensitive to oxidative stress, which is the basis for many neurodegenerative disease pathophysiologies. The posttranscriptional basis for neuronal differentiation and behavior is not well characterized. The steady-state levels of mRNA are outcomes of an interplay between RNA transcription and decay. However, the correlation between mRNA transcription, translation, and stability remains elusive. We utilized a SH-SY5Y-based neural differentiation model that is widely used to study neurodegenerative diseases. After neuronal differentiation, we observed enhanced sensitivity of mature neurons to mitochondrial stresses and ferroptosis induction. We employed a newly developed simplified mRNA stability profiling technique to explore the role of mRNA stability in SH-SY5Y neuronal differentiation model. Transcriptome-wide mRNA stability analysis revealed neural-specific RNA stability kinetics. Our analysis revealed that mRNA stability could either exert the buffering effect on gene products or change in the same direction as transcription. Importantly, we observed that changes in mRNA stability corrected over or under transcription of mRNAs to maintain mRNA translation dynamics. Furthermore, we conducted integrative analysis of our mRNA stability data set, and a published CRISPR-i screen focused on neuronal oxidative stress responses. Our analysis unveiled novel neuronal stress response genes that were not evident at the transcriptional or translational levels. SEPHS2 emerged as an important neuronal stress regulator based on this integrative analysis. Motif analysis unveiled SAMD4A as a major regulator of the dynamic changes in mRNA stability observed during differentiation. Knockdown of SAMD4A impaired neuronal differentiation and influenced the response to oxidative stress. Mechanistically, SAMD4A was found to alter the stability of several mRNAs. The novel insights into the interplay between mRNA stability and cellular behaviors provide a foundation for understanding neurodevelopmental processes and neurodegenerative disorders and highlight dynamic mRNA stability as an important layer of gene expression.

Recent progress in mRNA cancer vaccines

The research and development of messenger RNA (mRNA) cancer vaccines have gradually overcome numerous challenges through the application of personalized cancer antigens, structural optimization of mRNA, and the development of alternative RNA-based vectors and efficient targeted delivery vectors. Clinical trials are currently underway for various cancer vaccines that encode tumor-associated antigens (TAAs), tumor-specific antigens (TSAs), or immunomodulators. In this paper, we summarize the optimization of mRNA and the emergence of RNA-based expression vectors in cancer vaccines. We begin by reviewing the advancement and utilization of state-of-the-art targeted lipid nanoparticles (LNPs), followed by presenting the primary classifications and clinical applications of mRNA cancer vaccines. Collectively, mRNA vaccines are emerging as a central focus in cancer immunotherapy, offering the potential to address multiple challenges in cancer treatment, either as standalone therapies or in combination with current cancer treatments.

Scaled codon usage similarity index: A comprehensive resource for crop plants

Over the past three decades species-specific codon usage bias has been used to optimize heterologous gene expression in the target host. However, synthesizing codon optimized gene for multiple species is not achievable due to the prohibitive expense of DNA synthesis. To address this challenge, grouping species with similar codon usage can reduce the need for species-specific codon optimised gene synthesis. We introduced Scaled Codon Usage Similarity (SCUS) index to standardize species similarity assessments based on codon usage profiles. By analysing the SCUS index of 77 plant nuclear genomes from 13 families, we identified codon usage patterns and similarities. We developed an online SCUS index database and a Consensus Relative Synonymous Codon Usage (CRSCU) calculator, available at https://pcud.plantcodon.info. The CRSCU calculator helps determine the most suitable codon usage pattern among two or more species. The SCUS index and CRSCU calculator will facilitate the development of multi-species expression systems, enabling the efficient expression of a single synthetic gene across various crop species. This innovation paves the way for cost-effective and efficient heterologous gene expression across diverse crop species.

Comparative genomic analyses reveal evidence for adaptive A-to-I RNA editing in insect Adar gene

Although A-to-I RNA editing leads to similar effects to A-to-G DNA mutation, nonsynonymous RNA editing (recoding) is believed to confer its adaptiveness by 'epigenetically' regulating proteomic diversity in a temporospatial manner, avoiding the pleiotropic effect of genomic mutations. Recent discoveries on the evolutionary trajectory of Ser>Gly auto-editing site in insect Adar gene demonstrated a selective advantage to having an editable codon compared to uneditable ones. However, apart from pure observations, quantitative approaches for justifying the adaptiveness of individual RNA editing sites are still lacking. We performed a comparative genomic analysis on 113 Diptera species, focusing on the Adar Ser>Gly auto-recoding site in Drosophila. We only found one species having a derived Gly at the corresponding site, and this occurrence was significantly lower than genome-wide random expectation. This suggests that the Adar Ser>Gly site is unlikely to be genomically replaced with G during evolution, and thus indicating the advantage of editable status over hardwired genomic alleles. Similar trends were observed for the conserved Ile>Met recoding in gene Syt1. In the light of evolution, we established a comparative genomic approach for quantitatively justifying the adaptiveness of individual editing sites. Priority should be given to such adaptive editing sites in future functional studies.

Engineering biology and automation-Replicability as a design principle

Applications in engineering biology increasingly share the need to run operations on very large numbers of biological samples. This is a direct consequence of the application of good engineering practices, the limited predictive power of current computational models and the desire to investigate very large design spaces in order to solve the hard, important problems the discipline promises to solve. Automation has been proposed as a key component for running large numbers of operations on biological samples. This is because it is strongly associated with higher throughput, and with higher replicability (thanks to the reduction of human input). The authors focus on replicability and make the point that, far from being an additional burden for automation efforts, replicability should be considered central to the design of the automated pipelines processing biological samples at scale-as trialled in biofoundries. There cannot be successful automation without effective error control. Design principles for an IT infrastructure that supports replicability are presented. Finally, the authors conclude with some perspectives regarding the evolution of automation in engineering biology. In particular, they speculate that the integration of hardware and software will show rapid progress, and offer users a degree of control and abstraction of the robotic infrastructure on a level significantly greater than experienced today.

Regulating translation in aging: from global to gene-specific mechanisms

Aging is characterized by a decline in various biological functions that is associated with changes in gene expression programs. Recent transcriptome-wide integrative studies in diverse organisms and tissues have revealed a gradual uncoupling between RNA and protein levels with aging, which highlights the importance of post-transcriptional regulatory processes. Here, we provide an overview of multi-omics analyses that show the progressive uncorrelation of transcriptomes and proteomes during the course of healthy aging. We then describe the molecular changes leading to global downregulation of protein synthesis with age and review recent work dissecting the mechanisms involved in gene-specific translational regulation in complementary model organisms. These mechanisms include the recognition of regulated mRNAs by trans-acting factors such as miRNA and RNA-binding proteins, the condensation of mRNAs into repressive cytoplasmic RNP granules, and the pausing of ribosomes at specific residues. Lastly, we mention future challenges of this emerging field, possible buffering functions as well as potential links with disease.

Codon optimality modulates cellular stress and innate immune responses triggered by exogenous RNAs

The COVID-19 mRNA vaccines demonstrated the power of mRNA medicines. Despite advancements in sequence design, evidence regarding the preferential use of synonymous codons on cellular stress and innate immune responses is lacking. To this end, we developed a proprietary codon optimality matrix to re-engineer the coding sequences of three luciferase reporters. We demonstrate that optimal mRNAs elicited dramatic increases in luciferase activities compared to non-optimal sequences. Notably, transfecting an optimal RNA affects the translation of other RNAs in the cell including control transcripts in dual luciferase assays. This held true in multiple cell lines and for an unrelated reporter. Further, non-optimal mRNAs preferentially activated innate immune pathways and the phosphorylation of the translation initiation factor eIF2α, a central event of the integrated stress response. Using nucleoside-modified or circular RNAs partially or fully abrogated these responses. Finally, we show that circularizing RNAs enhances both RNA lifespan and durability of protein expression. Our results show that RNA sequence, composition, and structure all govern RNA translatability. However, we also show that RNA sequences with poor codon optimality are immunogenic and induce cellular stress. Hence, RNA sequence engineering, chemical, and topological modifications must all be combined to elicit favorable therapeutic outcomes.

Specific tRNAs promote mRNA decay by recruiting the CCR4-NOT complex to translating ribosomes

The CCR4-NOT complex is a major regulator of eukaryotic messenger RNA (mRNA) stability. Slow decoding during translation promotes association of CCR4-NOT with ribosomes, accelerating mRNA degradation. We applied selective ribosome profiling to further investigate the determinants of CCR4-NOT recruitment to ribosomes in mammalian cells. This revealed that specific arginine codons in the P-site are strong signals for ribosomal recruitment of human CNOT3, a CCR4-NOT subunit. Cryo-electron microscopy and transfer RNA (tRNA) mutagenesis demonstrated that the D-arms of select arginine tRNAs interact with CNOT3 and promote its recruitment whereas other tRNA D-arms sterically clash with CNOT3. These effects link codon content to mRNA stability. Thus, in addition to their canonical decoding function, tRNAs directly engage regulatory complexes during translation, a mechanism we term P-site tRNA-mediated mRNA decay.

Unveiling RNA structure-mediated regulations of RNA stability in wheat

Despite the critical role of mRNA stability in post-transcriptional gene regulation, research on this topic in wheat, a vital agricultural crop, remains unclear. Our study investigated the mRNA decay landscape of durum wheat (Triticum turgidum L. ssp. durum, BBAA), revealing subgenomic asymmetry in mRNA stability and its impact on steady-state mRNA abundance. Our findings indicate that the 3' UTR structure and homoeolog preference for RNA structural motifs can influence mRNA stability, leading to subgenomic RNA decay imbalance. Furthermore, single-nucleotide variations (SNVs) selected for RNA structural motifs during domestication can cause variations in subgenomic mRNA stability and subsequent changes in steady-state expression levels. Our research on the transcriptome stability of polyploid wheat highlights the regulatory role of non-coding region structures in mRNA stability, and how domestication shaped RNA structure, altering subgenomic mRNA stability. These results illustrate the importance of RNA structure-mediated post-transcriptional gene regulation in wheat and pave the way for its potential use in crop improvement.

Translation elongation inhibitors stabilize select short-lived transcripts

Translation elongation inhibitors are commonly used to study different cellular processes. Yet, their specific impact on transcription and mRNA decay has not been thoroughly assessed. Here, we use TimeLapse sequencing to investigate how translational stress impacts mRNA dynamics in human cells. Our results reveal that a distinct group of transcripts is stabilized in response to the translation elongation inhibitor emetine. These stabilized mRNAs are short-lived at steady state, and many of them encode C2H2 zinc finger proteins. The codon usage of these stabilized transcripts is suboptimal compared to other expressed transcripts, including other short-lived mRNAs that are not stabilized after emetine treatment. Finally, we show that stabilization of these transcripts is independent of ribosome quality control factors and signaling pathways activated by ribosome collisions. Our data describe a group of short-lived transcripts whose degradation is particularly sensitive to the inhibition of translation elongation.

Selection on synonymous codon usage in soybean (Glycine max) WRKY genes

The WRKY transcription factor gene family in soybean [Glycine max (L.) Merr.] (GmWRKY) is critical for the plant's development and stress responses. This study examines the evolutionary dynamics of the GmWRKY gene family, focusing on its synonymous codon usage bias (CUB) in a comprehensive set of 179 coding sequences. CUB was analyzed using various indices, revealing a preference for A/T-ending codons and relatively low codon bias. Codon adaptation index (CAI) analysis suggested that these genes are optimized for efficient translation despite relatively low bias, reflecting a balance between codon diversity and translation efficiency. Neutrality and NC plots indicated that selective forces dominate over mutational forces in shaping codon usage, while selection signature analysis showed purifying selection being prevalent across the gene family. However, episodic positive selection was also detected in certain clades, highlighting potential adaptive diversification in response to environmental stress. Additionally, promoter binding site analysis uncovered correlations between codon usage and transcriptional regulation, indicating a context-dependent relationship between CUB and gene expression. Phylogenetic analysis identified 11 well-supported clades in the modern GmWRKY gene family and ancestral sequence reconstruction revealed more relaxed codon preferences and reduced selection constraints in modern GmWRKY genes, potentially linked to neofunctionalization and adaptation to environmental changes. These findings provide a framework for optimizing gene expression in transgenic soybean crops with resilience. Further functional validation of positively selected genes is recommended to elucidate their role in stress responses.