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Definition of the human mitochondrial TOM interactome reveals TRABD as a new interacting protein.

The mitochondrial proteome arises from dual genetic origins. Nuclear-encoded proteins need to be transported across or inserted into two distinguished membranes, and the translocase of the outer mitochondrial membrane (TOM) complex represents the main translocase in the outer mitochondrial membrane. Its composition and regulation have been extensively investigated within yeast cells. However, we have little knowledge of the TOM complex composition within human cells. Here, we have defined the TOM interactome in a comprehensive manner using biochemical approaches to isolate the TOM complex in combination with quantitative mass spectrometry analyses. With these studies, we defined the pleiotropic nature of the human TOM complex, including new interactors, such as TRABD. Our studies provide a framework to understand the various biogenesis pathways that merge at the TOM complex within human cells.

Humans

Nested Admixture During and After the Trans-Atlantic Slave Trade on the Island of São Tomé.

Human genetic admixture, involving the contact between two or more previously isolated populations, can be a complex process influenced by social dynamics. In this study, we aim to reconstruct complex admixture histories in São Tomé, an island in the Gulf of Guinea where the Portuguese established one of the first plantation-based slave societies. Since the 15th century, migration waves from Africa and Europe, slavery, marooning, and indentured labour led to profound demographic shifts and social stratification on the island. Examining 2.5 million SNPs newly genotyped in 96 São Toméans, we observed patterns of genetic differentiation that were more complex than those of other populations descended from enslaved Africans on either side of the Atlantic. Using local ancestry inference and Identical-by-Descent methods, we identified five genetic clusters in São Tomé and reconstructed shared ancestries between each cluster and 70 African and European population samples, including an extensive sample from the Cabo Verde archipelago. Our findings align with historical records, retracing the major slave trade routes and labour-driven migrations after the abolition of slavery. We also identified gene flow between recently admixed groups that were previously isolated on the island. We call this process, creating multiple layers of genetic ancestry in admixed genomes, nested admixture. We suggest that changing social structures in São Tomé transformed the genetic structure of its population and influenced the admixture process. This study demonstrates how successive admixture and isolation events during and after the Trans-Atlantic Slave Trade shaped extant genetic diversity patterns at local scale in Africa.

Humans

Molecular architecture and spatial organization of proteasomes in the human sperm nucleus.

Proteasomes are fundamental for protein homeostasis and genome integrity and essential in spermatogenesis and fertilization. However, their presence, composition and role within the sperm nucleus are a subject of debate. Here we use in situ cryo-electron tomography in human sperm cells to elucidate the molecular architecture of nuclear proteasomes, which cluster in DNA-free, nuclear cavities within the sperm nucleus. We show that the main population of proteasomes consists of 20S core particles, with a smaller fraction of 20S capped by PA200 activator. Using single-particle cryo-electron microscopy of purified native human sperm proteasomes, we elucidate the features of the essential testis-specific subunit α4s, reporting the presence of a unique splice variant. We resolve a native peptide in the catalytic β2 subunit, providing insight into the proteolysis mechanism and PA200-mediated enhancement of trypsin activity. We show nuclear enrichment of proteasomes during sperm-cell differentiation in human testis tissue, with 20S and PA200 clustering following meiosis, at the spermatid stage. Our findings shed light on the organization and compositional diversity of nuclear proteasomes in human sperm cells, as well as their catalytic function.

Humans

A graph-based approach for the visualisation and analysis of bacterial pangenomes.

BACKGROUND: The advent of low cost, high throughput DNA sequencing has led to the availability of thousands of complete genome sequences for a wide variety of bacterial species. Examining and interpreting genetic variation on this scale represents a significant challenge to existing methods of data analysis and visualisation. RESULTS: Starting with the output of standard pangenome analysis tools, we describe the generation and analysis of interactive, 3D network graphs to explore the structure of bacterial populations, the distribution of genes across a population, and the syntenic order in which those genes occur, in the new open-source network analysis platform, Graphia. Both the analysis and the visualisation are scalable to datasets of thousands of genome sequences. CONCLUSIONS: We anticipate that the approaches presented here will be of great utility to the microbial research community, allowing faster, more intuitive, and flexible interaction with pangenome datasets, thereby enhancing interpretation of these complex data.

Bacteria

Runaway evolution of telomeres in ascomycetous yeasts was accompanied by the replacement of ancestral telomeric proteins.

Telomeres are crucial parts of eukaryotic chromosomes, contributing to DNA replication, chromosome segregation, and genome stability. While in most phylogenetic lineages, telomere-maintenance systems are conserved, ascomycetous yeasts exhibit a high degree of variability in telomeric repeats and the associated proteins. The determinants that enabled this divergent evolutionary process, however, have been unclear. Here, we show that DNA-binding properties of yeast telomere-binding proteins (TBPs) support the scenario where the gradual divergence of telomeric repeats led to their replacement. We analyzed the DNA-protein interactions between Tay1p from Yarrowia lipolytica, Rap1p from Saccharomyces cerevisiae, and Taz1p from Schizosaccharomyces pombe and a set of telomeric repeats from several yeast species and delineated how the ancestral (Tay1p-like) TBPs were replaced by Rap1p (in budding yeasts) or Taz1p (in fission yeasts). We also postulate two different driving forces for these replacements: (i) Tay1p-to-Rap1p transition appears to be driven by differences in sequence preferences of Tay1p and Rap1p, while (ii) Taz1p became the principal TBP in fission yeast presumably due to its DNA-binding flexibility. Together, our results suggest that in telomeric DNA-protein complexes, the replacement of protein component triggered by the initial variation in DNA sequence space opens the door to further divergence in a runaway-style evolution.

Telomere-Binding Proteins

Germline determinants of risk and molecular subtype in young-onset lung cancer.

Young-onset lung cancer is enriched for never-smoking and oncogene-driven tumors, yet its inherited genetic basis remains poorly defined. We performed germline whole-genome sequencing in 251 young-onset lung cancer cases (median age 37), which we jointly analyzed with never-smoking cases (n=196; median age 68) and cancer-free controls (n=1,883). We identified enrichments of rare deleterious coding variants across 55 cancer-related gene sets, including EGFR/ERBB2 signaling and genes implicated by prior lung cancer GWAS. Exome-wide analyses of rare coding variants affirmed TP53 as a penetrant lung cancer predisposition gene (odds ratio [OR]=36.1, p=1.02x10-7) and discovered two novel exome-wide significant tumor subtype-dependent associations: IREB2 in cases with fusion-driven tumors (p=1.39x10-6) and SMAD6 in fusion-negative tumors (p=2.05x10-6). Structural variants contributed distinct risk, with enrichment in constrained, lung-expressed genes (OR=5.79, p=5.8x10-5) and very large germline deletions being markedly enriched in cases with fusion-driven tumors. Polygenic risk scores for lung cancer were inversely correlated with rare variant burden, consistent with additive risk from rare and common variants. Collectively, these findings delineate a complex germline architecture underlying susceptibility and molecular subtype in young-onset lung cancer.

Journal Article

Cilia defects upon loss of WDR4 are linked to proteasomal hyperactivity and ubiquitin shortage.

The WD repeat-containing protein 4 (WDR4) has repeatedly been associated with primary microcephaly, a condition of impaired brain and skull growth. Often, faulty centrosomes cause microcephaly, yet aberrant cilia may also be involved. Here, we show using a combination of approaches in human fibroblasts, zebrafish embryos and patient-derived cells that WDR4 facilitates cilium formation. Molecularly, we associated WDR4 loss-of-function with increased protein synthesis and concomitant upregulation of proteasomal activity, while ubiquitin precursor pools are reduced. Inhibition of proteasomal activity as well as supplementation with free ubiquitin restored normal ciliogenesis. Proteasome inhibition ameliorated microcephaly phenotypes. Thus, we propose that WDR4 loss-of-function impairs head growth and neurogenesis via aberrant cilia formation, initially caused by disturbed protein and ubiquitin homeostasis.

Animals

AEGIS: an annotation extraction and genomic integration resource.

MOTIVATION: Genome annotation files (GFF3/GTF) are the standard for storing genomic feature data, yet their flexibility often results in formatting inconsistencies that create bottlenecks for downstream bioinformatics analyses. A robust, unified framework is required to parse, standardise, and validate these files to ensure interoperability and facilitate complex comparative genomic tasks. RESULTS: We present AEGIS (Annotation Extraction and Genomic Integration Suite), a comprehensive toolkit designed to parse, correct, and standardise genome annotations. Beyond quality control, AEGIS provides advanced modules for flexible feature extraction (e.g., coding sequences, promoters) and comparative genomic analysis. Uniquely, it integrates multiple lines of evidence, including sequence homology, synteny, and coordinate-based lift-overs, to assess gene model correspondence and infer orthology. We demonstrate the utility of AEGIS by quantifying complex structural changes between Arabidopsis annotation versions and identifying high-confidence orthologues across diverse plant genomes. AVAILABILITY: AEGIS is implemented in Python. Source code and documentation are freely available under the GPL-3 license at https://github.com/Tomsbiolab/aegis and as a Docker container at https://hub.docker.com/r/tomsbiolab/aegis. The package is also available on PyPI (pip install aegis-bio).

Software

Phylogenomic Analyses Reveal that Panguiarchaeum Is a Clade of Genome-Reduced Asgard Archaea Within the Njordarchaeia.

The Asgard archaea are a diverse archaeal phylum important for our understanding of cellular evolution because they include the lineage that gave rise to eukaryotes. Recent phylogenomic work has focused on characterizing the diversity of Asgard archaea in an effort to identify the closest extant relatives of eukaryotes. However, resolving archaeal phylogeny is challenging, and the positions of 2 recently described lineages-Njordarchaeales and Panguiarchaeales-are uncertain, in ways that directly bear on hypotheses of early evolution. In initial phylogenetic analyses, these lineages branched either with Asgards or with the distantly related Korarchaeota, and it has been suggested that their genomes may be affected by metagenomic contamination. Resolving this debate is important because these clades include genome-reduced lineages that may help inform our understanding of the evolution of symbiosis within Asgard archaea. Here, we performed phylogenetic analyses revealing that the Njordarchaeales and Panguiarchaeales constitute the new class Njordarchaeia within Asgard archaea. We found no evidence of metagenomic contamination affecting phylogenetic analyses. Njordarchaeia exhibit hallmarks of adaptations to (hyper-)thermophilic lifestyles, including biased sequence compositions that can induce phylogenetic artifacts unless adequately modeled. Panguiarchaeum is metabolically distinct from its relatives, with reduced metabolic potential and various auxotrophies. Phylogenetic reconciliation recovers a complex common ancestor of Asgard archaea that encoded the Wood-Ljungdahl pathway. The subsequent loss of this pathway during the reductive evolution of Panguiarchaeum may have been associated with the switch to a symbiotic lifestyle, potentially based on H2-syntrophy. Thus, Panguiarchaeum may contain the first obligate symbionts within Asgard archaea besides the lineage leading to eukaryotes.

Phylogeny

Historical introgression as a driver of diversification of diploid Picris (Compositae) in the Mediterranean Basin.

The Mediterranean Basin is recognized as one of the world's most prominent biodiversity hotspots, where past climatic changes have driven range shifts, secondary contact between populations, and gene exchange. This study investigates the impact of historical introgression on the diversification of diploid members of the genus Picris (Compositae). Using nuclear and plastid genome data obtained through the Hyb-Seq approach, we assess whether introgression contributed to the evolution of the Mediterranean Picris, potentially giving rise to multiple regional endemics. We also test whether introgression was associated with the transfer of traits such as life strategy and fruit morphology, which are involved in habitat-specific adaptation. Phylogenetic network analysis revealed two major introgression events that shaped evolutionary trajectories within the genus. The earliest and most complex events involved the Turkish endemic P. campylocarpa, which hybridized with the most recent common ancestor (MRCA) of the P. cyprica-P. pauciflora lineage and with the MRCA of the B1 subclade, comprising the P. hieracioides group and the P. scaberrima-P. strigosa lineage. The latter introgression preceded shifts from iteroparity to semelparity and from heterocarpy to homocarpy, ruling out an adaptive introgression origin for these traits. Nevertheless, all detected historical introgression events contributed to the diversification of diploid Picris taxa.

Diploidy

Dual recognition drives site-directed G-quadruplex stabilization: Oligonucleotide design in G4 ligand-oligonucleotide conjugates.

G-quadruplex (G4) DNA structures are increasingly recognized for their roles in transcriptional regulation and genome stability, making them attractive therapeutic targets. Selective recognition of individual G4s remains challenging due to the high structural similarity among G4 motifs. G4 Ligand-Oligonucleotides conjugates (GL-Os) address this challenge by combining small-molecule G4 ligands with the sequence specificity of oligonucleotides, targeting sequences flanking the intended G4 target. Here, we systematically investigate how oligonucleotide length, backbone composition, and sequence complementarity govern GL-O binding, selectivity, and G4 stabilization. We show that effective G4 recognition depends on the interdependence between oligonucleotide hybridization and G4 ligand binding, such that both elements cooperatively reinforce complex stability and site specificity. Longer oligonucleotides promote more stable complexes and stronger G4 stabilization, whereas central mismatches disrupt this dual-recognition mechanism. Replacement of DNA with peptide nucleic acids (PNAs) enhances binding strength, thermal stability, and metabolic stability. Importantly, ligand conjugation redirects PNA oligonucleotides from nonspecific polymerase stalling toward selective G4 stabilization. Finally, we demonstrate receptor-mediated cellular uptake of modified GL-Os, supporting the feasibility of cellular delivery while highlighting remaining delivery barriers. Together, these findings show the molecular design principles governing GL-O behavior and provide a foundation for the future development and evaluation of selective G4-targeting therapeutics.

G-quadruplex DNA

Dysregulation of the serum and IgG N-glycome in decompensated cirrhosis and its association with Model for End-Stage Liver Disease-Sodium (MELD-Na).

BACKGROUND AND AIMS: N-glycans modulate glycoprotein structure and function and are altered during chronic inflammation. We sought to define the extent of serum and IgG N-glycan disruption in patients with decompensated liver cirrhosis from alcohol-related liver disease (ALD), primary sclerosing cholangitis (PSC), and ALD-related hepatocellular carcinoma (HCC). Finally, we aimed to examine whether serum and IgG glycosylation is associated with changes in Model for End-stage Liver Disease-Sodium (MELD-Na) scores, a clinical marker used to prioritise liver transplantation. METHODS: Serum samples were obtained from patients with ALD (n = 17), PSC (n = 7), ALD-related HCC (n = 4), and healthy controls (n = 10). N-glycans were released, fluorescently labelled, and profiled by hydrophilic interaction ultra performance liquid chromatography (HILIC-UPLC). Chromatograms were integrated into 46 and 23 glycan peaks for serum and IgG respectively. These peaks and their associated glycosylation traits were statistically compared with healthy controls using age- and sex-adjusted linear regression models. RESULTS: In serum, decompensated cirrhosis shows statistically significant shifts toward less complex, agalactosylated and asialylated biantennary glycans, accompanied by significant losses of highly branched, galactosylated and sialylated structures. IgG mirrored this pattern, which is characteristic of a pro-inflammatory signature, with increased agalactosylation and bisected glycan levels, along with reduced levels of digalactosylated and sialylated species. N-glycan profiles showed significant associations with MELD-Na scores, indicating that inflammatory processes in decompensated liver cirrhosis continue to reshape serum glycoproteins. CONCLUSION: Decompensated liver cirrhosis shows profound remodelling of serum and IgG N-glycans. These data establish a reference framework for terminal glycomic disruption in liver disease and highlight the potential value of incorporating glycosylation analysis into broader assessments of liver disease progression.

Humans

Toward the clinical application of long-read sequencing in repeat-expansion disorders.

Repeat-expansion disorders (REDs) are a mechanistically and clinically well-defined subgroup of rare diseases caused by the expansion of short tandem repeats (STRs). These expansions can exceed several kilobases and show complex features, such as noncanonical secondary structures, somatic instability, repeat interruptions and allele-specific methylation. These characteristics are highly relevant for understanding disease mechanisms, clinical variability, prognosis and potentially therapeutic decision-making, but cannot be fully resolved using traditional diagnostic methods or short-read sequencing technologies. By contrast, long-read sequencing (LRS) enables accurate investigation of STR complexity in a single assay, facilitates the discovery of new pathogenic repeat expansions and drives advances in diagnostics, clinical and basic research, which may allow for better patient stratification in future clinical trials. This Perspective discusses recent LRS-driven discoveries, methodological and bioinformatic advances, and emerging diagnostic applications to illustrate the potential of LRS in reshaping both research and clinical practice.

Humans

pmultiqc: An Open-Source, Lightweight, and Metadata-Oriented QC Reporting Library for MS Proteomics.

The increasing scale and complexity of proteomics data demand robust, scalable, and interpretable quality control (QC) frameworks to ensure data reliability and reproducibility. Here, we present pmultiqc, an open-source Python package that standardizes and generates web-based QC reports across multiple proteomics data analysis platforms. Built on top of the widely adopted MultiQC framework, pmultiqc offers specialized modules tailored to mass spectrometry workflows, with full initial support for quantms, DIA-NN, MaxQuant/MaxDIA, FragPipe, and mzIdentML/mzML-based pipelines. The package computes a wide range of QC metrics, including raw intensity distributions, identification rates, retention time consistency, and missing value patterns, and presents them in interactive, publication-ready reports. By leveraging sample metadata in the Sample and Data Relationship Format format, pmultiqc enables metadata-aware QC and introduces, for the first time in proteomics, QC reports and metrics guided by standardized sample metadata. Its modular architecture allows easy extension to new workflows and formats. Alongside comprehensive documentation and examples for running pmultiqc locally or integrated into existing workflows, we offer a cloud-based service that enables users to generate QC reports from their own data or public PRIDE datasets.

Proteomics

Linear ubiquitination prevents lipodystrophy and obesity-associated metabolic syndrome.

Adipocyte hypertrophy during obesity triggers chronic inflammation, leading to metabolic disorders. However, the role of adipocyte-specific inflammatory signaling in metabolic syndrome remains unclear. The linear ubiquitin chain assembly complex, LUBAC, is an E3-ligase that generates nondegradative linear ubiquitination (Lin-Ub). LUBAC regulates NF-κB/MAPK-driven inflammation and prevents cell death triggered by immune receptors like TNF receptor-1. Here, we show that mice lacking HOIP, the Lin-E3 ligase catalytic subunit of LUBAC, in adipocytes (HoipA-KO) display lipodystrophy and heightened susceptibility to obesity-induced metabolic syndrome, particularly metabolic dysfunction-associated steatotic liver disease (MASLD). Mechanistically, loss of HOIP attenuates TNF-induced NF-κB activation and promotes cell death in human adipocytes. Inhibiting caspase-8-mediated cell death is sufficient to prevent lipodystrophy and MASLD in HoipA-KO obese mice. HOIP expression in adipose tissue positively correlates with metabolic fitness in obese individuals. Overall, our findings reveal a fundamental developmental role for Lin-Ub in adipocytes by mitigating cell death-driven adipose tissue inflammation and protecting against obesity-related metabolic syndrome.

Animals

Zone equalisation normalisation for improved alignment of epigenetic signal.

MOTIVATION: High-throughput genomic technologies have transformed our understanding of biological systems, yet direct comparison and visualisation of these complex datasets remains challenging. Existing normalisation methods often fail to align genomic signal across samples due to sensitivity to sequencing depth differences and localised high-signal artefacts, leading to inconsistent replicate behaviour and increased downstream variability. RESULTS: We introduce Zone Equalisation Normalisation (ZEN), a novel approach designed to improve cross-sample signal alignment of genomic data. ZEN rescales genomic signal based on variance estimated within biologically enriched regions, reducing the influence of extreme outliers while preserving underlying biological structure. Using a diverse collection of data and our new genome-wide benchmarking approach, we reveal that ZEN improves biological and technical replicate alignment across the majority of tested conditions and experimental platforms. We further show that this improved signal comparability is associated with fewer differential accessibility calls between technical replicates and a more conservative set of biological differences. Together, these results demonstrate that ZEN provides a complementary framework to improve the accuracy and reliability of genomic data analysis and that normalisation choice can affect downstream analyses and biological interpretation. AVAILABILITY AND IMPLEMENTATION: ZEN is available as an open-source Python package via conda and PyPI. Source code, documentation, tutorials, and code to reproduce the analyses are available at https://github.com/Genome-Function-Initiative-Oxford/Zone-Equalisation-Normalisation and Zenodo (https://doi.org/10.5281/zenodo.21067751).

Epigenesis, Genetic

Spatially Distinct Bone Marrow Sites Are Asymmetrically Impacted by Inflammatory Cardiovascular Disease.

Cardiovascular disease, a leading cause of mortality globally, is increasingly recognized to involve complex bone marrow-driven inflammatory mechanisms, yet the impact on spatially distinct bone marrow sites and comorbidities remains poorly understood. To address this, we developed MarrowMet, a methodology for whole-body, site-specific quantification of bone marrow activity. The approach involves intravenously injecting the metabolic tracer 18F-fluorodeoxyglucose (18F-FDG) in mice, followed by bone excision to quantify site-specific bone marrow activity, with values then superimposed on a whole-body mouse atlas. After establishing that 18F-FDG bone marrow uptake strongly correlated with inflammatory activity, we applied MarrowMet to map site-specific activation patterns across diverse cardiovascular pathologies, including mouse models of inflammatory atherosclerosis, acute ischemic events, acute respiratory distress syndrome, metabolic syndrome, and aging. MarrowMet guided the selection of bone marrow regions of interest for in-depth mass cytometric analyses, with the skull and sternum emerging as critical sites exhibiting distinct immune and metabolic profiles in cardiovascular disease. These results challenge the prevailing view that femoral marrow represents systemic activity. Together, this work lays a foundation for whole-body exploration of bone marrow heterogeneity, yielding critical insights into cardiovascular disease and associated inflammatory responses, and MarrowMet can be readily adopted to profile other immune mechanisms in a variety of pathologies, including cancer and autoimmune diseases.

(18)F-FDG

TamL is a Key Player of the Outer Membrane Homeostasis in Bacteroidota.

In Proteobacteria, the outer membrane protein TamA and the inner membrane-anchored protein TamB form the Translocation and Assembly Module (TAM) complex, which facilitates the transport of autotransporters, virulence factors, and likely lipids across the two membranes. In Bacteroidota, TamA is replaced by TamL, a TamA-like lipoprotein with a lipid modification at its N-terminus that likely anchors it to the outer membrane. This structural difference suggests that TamL may have a distinct function compared to TamA. However, the role of TAM in bacterial phyla other than Proteobacteria remains unexplored. Our study aimed to elucidate the function of TamL in Flavobacterium johnsoniae, an environmental Bacteroidota. Unlike its homologs in Proteobacteria, we found that TamL and TamB are essential in F. johnsoniae. Through genetic, phenotypic, proteomic, and lipidomic analyses, we show that TamL depletion severely compromises outer membrane integrity, as evidenced by reduced cell viability, altered cell shape, increased susceptibility to membrane-disrupting agents, and elevated levels of outer membrane lipoproteins. Notably, we did not observe an overall decrease in the levels of β-barrel outer membrane proteins, nor substantial alterations in outer membrane lipid composition. By pull-down assays, we found TamL co-purifying with TamB in F. johnsoniae, suggesting an interaction. Furthermore, we found that while TamL and TamB monocistronic genes are conserved among Bacteroidota, only some species encode multiple TamL, TamB and TamA proteins. To our knowledge, this study is the first to provide functional insights into a TAM subunit beyond Proteobacteria.

Bacterial Outer Membrane Proteins