Influenza A virus circumvents the innate immune response through the sequestration of double-stranded RNA.

Double-stranded RNA (dsRNA), which induces an innate immune response against viral infections, is rarely detected in influenza A virus (IAV)-infected cells. Nevertheless, we previously reported that the influenza A viral ribonucleoprotein (vRNP) complex generates looped dsRNAs during RNA synthesis . This finding suggests that IAV possesses a specific mechanism for sequestering dsRNA within infected cells, thereby enabling viral evasion of the innate immune response.

Differential cell survival outcomes in response to diverse amino acid stress.

Amino acid (AA) detection is fundamental for cellular function, balancing translation demands, biochemical pathways, and signaling networks. Although the GCN2 and mTORC1 pathways are known to regulate AA sensing, the global cellular response to AA deprivation remains poorly understood, particularly in non-transformed cells, which may exhibit distinct adaptive strategies compared with cancer cells. Here, we employed murine pluripotent embryonic stem (ES) cells as a model system to dissect responses to AA stress.

Redefining ALS: Large-scale proteomic profiling reveals a prolonged pre-diagnostic phase with immune, muscular, metabolic, and brain involvement.

Background: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with a largely unknown duration and pathophysiology of the pre-diagnostic phase, especially for the common non-monogenic form.

Methods: We leveraged the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort with up to 30 years of follow-up to identify incident ALS cases across five European countries. Pre-diagnostic plasma samples from initially healthy participants underwent high-throughput proteomic profiling (7,285 protein markers, SomaScan).

Clonal haematopoiesis of indeterminate potential and mortality in coronary artery disease.

Background And Aims: Clonal haematopoiesis of indeterminate potential (CHIP) has been associated with cardiovascular risk, but its prognostic relevance and mechanistic role in coronary artery disease (CAD) remains incompletely understood. This study investigated the association between CHIP and all-cause mortality in CAD and explored the cellular and molecular mechanisms, focusing on TET2 mutations.

Methods: Targeted deep sequencing of 13 CHIP driver genes in 8612 patients with angiographically confirmed CAD was performed.

Spatial TCR clonality and clonal expansion in the in situ microenvironment of non-small cell lung cancer.

Background: T-cell activation and clonal expansion are essential to effective immunotherapy responses in non-small cell lung cancer (NSCLC). The distribution of T-cell clones may offer insights into immunogenic mechanisms and imply potential prognostic and predictive information.

Methods: We analyzed α/β T-cell receptor (TCR) clonality using RNA-sequencing of bulk frozen tumor tissue from 182 patients with NSCLC.

Cryo-focused ion beam milling for cryo-electron tomography: Shaping the future of in situ structural biology.

Cryo-focused ion beam instruments to produce cellular thin sections for subsequent imaging by cryo-electron tomography have become an integral part of the methodologies for in situ structural biology, enabling high-resolution imaging of biological structures in their native environment. The application of these instruments has opened windows into cells that allowed unprecedented insights into the ultrastructure of cells and more recently, small multicellular organisms and tissues. While great strides have been made in the characterization of cryo-FIB milling and the streamlining of workflows with these tools, many limitations and technical challenges remain to be resolved.

Calcium homeostasis role in preserving sperm function and metabolic activity during liquid storage of pig semen.

Calcium (Ca) is known as a key regulator of sperm physiology, playing a crucial role in capacitation, hyperactivation, the acrosome reaction, and fertilisation. Despite this, whether it shapes the sperm's ability to withstand liquid preservation has not been addressed. Herein, we investigated how altering Ca availability to pig sperm during storage at 17 °C affects their quality and metabolic activity.

High-quality de novo genome assembly and functional genomic insights into Thermobifida alba DSM43795, a mesophilic actinobacterium isolated from garden soil.

Thermobifida alba DSM43795, a mesophilic actinobacterium isolated from garden soil, plays a vital role in lignocellulose degradation and holds biotechnological and pharmaceutical potential. We present a high-quality, complete de novo genome assembly of T. alba DSM43795 using combined PacBio long-read and Illumina short-read sequencing, resulting in a single circular chromosome of 4.

Cryo-light microscopy with angstrom precision deciphers structural conformations of PIEZO1 in its native state.

Investigations based on cryo-electron microscopy (cryo-EM), atomic force microscopy, and super-resolution microscopy reveal a symmetric trimer with propeller-like blades for the mechanosensitive ion channel PIEZO. However, a conclusive understanding of its conformations in the cell membrane is lacking. Here, we implement a high-vacuum cryogenic shuttle to transfer shock-frozen cell membranes in and out of a cryostat designed for single-particle cryo-light microscopy (spCryo-LM).

The small GTPase Ran defines nuclear pore complex asymmetry.

Nuclear pore complexes (NPCs) bridge across the nuclear envelope and mediate nucleocytoplasmic exchange. They consist of hundreds of nucleoporin building blocks and exemplify the structural complexity of macromolecular assemblies. To ensure transport directionality, different nucleoporin complexes are attached to the cytoplasmic and nuclear face of the NPC.

Structural basis for E4 enzyme Ufd2-catalyzed K48/K29 branched ubiquitin chains.

E4 enzymes amplify and remodel ubiquitin chain signals beyond the conventional E1-E2-E3 cascade. The first identified E4 enzyme Ufd2 preferentially catalyzes K48/K29 branched ubiquitin chains, yet the structural mechanism remains unknown. Here, we combined chemical biology and cryo-electron microscopy to visualize stable intermediates in Ufd2 loading ubiquitin at K48 of proximal ubiquitin on K29-linked di- and triubiquitin.

A novel hybrid high speed mass spectrometer allows rapid translation from biomarker candidates to targeted clinical tests using 15N labeled proteins.

Recent developments in affinity binder or mass spectrometry (MS)-based plasma proteomics are now producing panels of potential biomarker candidates for diagnosis or prognosis. However, clinical validation and implementation of these biomarkers remain limited by the reliance on dated triple quadrupole MS technology. Here, we evaluate a novel hybrid high-speed mass spectrometer, Stellar MS, which integrates the robustness of triple quadrupoles with the enhanced capabilities of an advanced linear ion trap analyzer.

Membraneless protocell confined by a heat flow.

In living cells, a complex mixture of biomolecules is assembled within and across membranes. This non-equilibrium state is maintained by sophisticated protein machinery, which imports food molecules, removes waste products and orchestrates cell division. However, it remains unclear how this complex cellular machinery emerged and evolved.

Building a Synthetic Cell Together.

Synthetic cells (SynCells) are artificial constructs designed to mimic cellular functions, offering insights into fundamental biology, as well as promising impact in the fields of medicine, biotechnology, and bioengineering. Achieving a functional SynCell from the bottom up, i.e.

iPSC-derived macrophages: An in vitro model to study human disease-relevant macrophage biology.

Human macrophages differ from their mouse counterparts in multiple metabolic pathways, surface protein expression, and transcription factor biology. Monocyte-derived macrophages (MDMs) from blood are generally used to study human macrophage biology in vitro. However, the use of MDMs as a human macrophage model is limited by donor-to-donor variability, total cell availability, preactivation effects, and relative resistance to genetic manipulation.

Inflammasome-independent IL-1β activation via staphopain A protease of Staphylococcus aureus.

Interleukin-1β (IL-1β) is a pivotal mediator of innate immunity, essential for orchestrating the acute inflammatory response. While the canonical activation of IL-1β involves cleavage of its inactive precursor (pro-IL-1β) by the inflammatory cysteine protease caspase-1, certain bacterial proteases, such as those secreted by group A Streptococcus and Pseudomonas aeruginosa, can also activate pro-IL-1β. In this study, we demonstrate that infection of human N/TERT-1 immortalized keratinocytes by Staphylococcus aureus induces IL-1β processing independently of the classical inflammasome pathways.

Structural analyses define the molecular basis of clusterin chaperone function.

Clusterin (apolipoprotein J), a conserved glycoprotein abundant in blood and cerebrospinal fluid, functions as a molecular chaperone and apolipoprotein. Dysregulation of clusterin is linked to late-onset Alzheimer disease. Despite its prominent role in extracellular proteostasis, the mechanism of clusterin function remained unclear.

MR1-ligand cross-linking identifies vitamin B6 metabolites as TCR-reactive antigens.

Major histocompatibility complex class I-related protein 1 (MR1) plays a central role in the immune recognition of infected cells and can mediate T cell detection of cancer. Knowledge of the nature of the ligands presented by MR1 is still sparse and has been limited by a lack of efficient approaches for MR1 ligand discovery. Here, we present a cross-linking strategy to investigate Schiff base-bound MR1 ligands.

A key role of polyamine metabolism in adipose tissue homeostasis that regulates obesity.

Background And Aims: Adipose tissue function is integral to systemic metabolic homeostasis. Excessive adipose tissue growth is associated with development of chronic low-grade inflammation and whole body dysmetabolism. The cell metabolic pathways regulating adipose tissue growth and homeostasis are little understood.

The EMC acts as a chaperone for membrane proteins.

Structure formation of membrane proteins is error-prone and thus requires chaperones that oversee this essential process in cell biology. The ER membrane protein complex (EMC) is well-defined as a transmembrane domain (TMD) insertase. In this study, we characterize an additional chaperone function of the EMC.

Sub-3 Å resolution protein structure determination by single-particle cryo-EM at 100 keV.

Cryoelectron microscopy (cryo-EM) has transformed structural biology by providing high-resolution insights into biological macromolecules. We report sub-3 Å resolution structures using the 100 keV Tundra cryo-TEM, equipped with the Falcon C direct electron detector (DED). This system combines advanced optics, extreme-brightness field emission gun (XFEG), and SP-TWIN lens to enhance coherence and resolution.

Altered translation elongation contributes to key hallmarks of aging in the killifish brain.

Aging is a major risk factor for neurodegeneration and is characterized by diverse cellular and molecular hallmarks. To understand the origin of these hallmarks, we studied the effects of aging on the transcriptome, translatome, and proteome in the brain of short-lived killifish. We identified a cascade of events in which aberrant translation pausing led to altered abundance of proteins independently of transcriptional regulation.