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Biology subjects

Karlsson, N.

Publications and source records attributed to Karlsson, N..

4 recordsLinked to original sources

Direct binding of arsenicals to nuclear transport factors disrupts nucleocytoplasmic transport

Human exposure to arsenicals is associated with devastating diseases such as cancer and neurodegeneration. At the same time, arsenic-based drugs are used as therapeutic agents. The ability of arsenic to directly bind to proteins is correlated with its toxic and therapeutic effects highlighting the importance of elucidating arsenic-protein interactions. In this study, we took a proteomic approach and identified 174 proteins that bind to arsenic in Saccharomyces cerevisiae. Proteins involved in nucleocytoplasmic transport were markedly enriched among the arsenic-binding proteins, and we demonstrate that arsenic-binding to nuclear import factors results in their relocation from the nuclear envelope and subsequent aggregation in the cytosol. Similarly, nuclear pore proteins that make up the nuclear pore complex mislocalized and aggregated in arsenic-exposed cells. Consequently, arsenic was shown to inhibit nuclear protein import and export. We propose a model in which arsenic-binding to nuclear transport factors leads to their mislocalization and aggregation, which disrupts nucleocytoplasmic transport and causes arsenic sensitivity.

cell biology↗

Sulfated host glycan recognition by carbohydrate sulfatases of the human gut microbiota

The vast microbial community that resides in the human colon, termed the human gut microbiota, performs important roles in maintaining host health. Sulfated host glycans comprise both a major nutrient source and important colonisation factors for this community. Carbohydrate sulfatases remove sulfate groups from glycans and are essential in many bacteria for the utilisation of sulfated host glycans. Additionally, carbohydrate sulfatases are also implicated in numerous host diseases, but remain some of the most understudied carbohydrate active enzymes to date, especially at the structural and molecular level. In this work, we analyse 7 carbohydrate sulfatases, spanning 4 subfamilies, from the human gut symbiont Bacteroides thetaiotaomicron, a major utiliser of sulfated host glycans, correlating structural and functional data with phylogenetic and environmental analyses. Together, these data begin to fill the knowledge gaps in how carbohydrate sulfatases orchestrate sulfated glycan metabolism within their environment.

biochemistry↗

e-workflow for recording of glycomic mass spectrometric data in compliance with reporting guidelines

Glycomics targets released glycans from proteins, lipids and proteoglycans. High throughput glycomics is based on mass spectrometry (MS) that increasingly depends on exchange of data with databases and the use of software. This requires an agreed format for accurately recording of experiments, developing consistent storage modules and granting public access to glycomic MS data. The introduction of the MIRAGE (Mimimum Requirement for A Glycomics Experiment) reporting standards for glycomics was the first step towards automating glycomic data recording. This report describes a glycomic e-infrastructure utilizing a well established glycomics recording format (GlycoWorkbench), and a dedicated web tool for submitting MIRAGE-compatible MS information into a public experimental repository, UniCarb-DR. The submission of data to UniCarb-DR should be a part of the submission process for publications with glycomics MSn that conform to the MIRAGE guidelines. The structure of this pipeline allows submission of most MS workflows used in glycomics.

bioinformatics↗

Genome Wide Study of Tardive Dyskinesia in Schizophrenia

Tardive dyskinesia (TD) is a severe condition characterized by repetitive involuntary movement of orofacial regions and extremities. Patients treated with antipsychotics typically present with TD symptomatology. Here, we conducted the largest GWAS of TD to date, by meta-analyzing samples of East-Asian, European, and African-American ancestry, followed by analyses of biological pathways and polygenic risk with related phenotypes. We identified a novel locus and three suggestive loci, implicating immune-related pathways. Through integrating trans-ethnic fine-mapping, we identified putative credible causal variants for three of the loci. Multivariate analyses of polygenic risk for TD supports the genetic susceptibility of TD, with relatively lower allele frequencies variants being associated with TD, beyond that of antipsychotic medication. Together, these findings provide new insights into the genetic architecture and biology of TD.

genomics↗