Biology subjects

Luzarowski, M.

Publications and source records attributed to Luzarowski, M..

9 recordsLinked to original sources

bioRxiv2026

Protein expression of short-chain dehydrogenases/reductases and their inducibility by flubendazole in Haemonchus contortus

Short-chain dehydrogenases/reductases (SDRs) constitute a large enzyme superfamily involved in endogenous metabolism and xenobiotic biotransformation. In the parasitic nematode Haemonchus contortus, SDRs may catalyze the carbonyl reduction of a benzimidazole anthelmintic flubendazole (FLU), whose increased reduction is associated with FLU resistance. This study thus investigated the constitutive expression of SDRs and their inducibility by FLU in drug-susceptible and benzimidazole-resistant strains of H. contortus. The expression of 23 sdr genes was analyzed by quantitative PCR, while targeted proteomic assays enabled the quantification of 15 SDR proteins. In adult nematodes, pronounced sex-dependent differences were detected at both transcript and protein levels. Resistance-associated alterations were less pronounced and were observed predominantly in males, with SDR9, SDR12, SDR15, and SDR20 displaying increased protein abundances in the resistant strain. Exposure to FLU induced only minimal transcriptional responses in juvenile stages, whereas adult nematodes exhibited marked sex- and strain-specific responses in the expression of SDRs. The strongest transcriptional effects were detected in resistant males, while significant protein-level changes following FLU treatment were observed exclusively in adults of the drug-susceptible strain. Notably, SDR9 and SDR20 combined resistance-associated expression patterns with responsiveness to FLU exposure. Taking together, the first targeted proteomic characterization of SDRs in H. contortus revealed several SDR isozymes with constitutive overexpression in resistant nematodes and/or inducibility by FLU, suggesting a potential role in adaptation to anthelmintic exposure.

molecular biology↗

bioRxiv2026

ESCRT proteins organise stress-induced organelle contact between endoplasmic reticulum and Golgi

ESCRT proteins remodel membranes at many cell organelles, including the endoplasmic reticulum (ER). Here, we investigate whether ESCRTs in budding yeast participate in stress-induced ER reorganisation. We find that ER stress triggers the formation of tubular ER subdomains that recruit various ESCRT proteins. Recruitment of the major ESCRT-III protein Snf7 is mediated by the ESCRT-associated protein Bro1, a homologue of human ALIX, in a manner that is mechanistically distinct from Bro1 function at endosomes. ESCRT-containing ER subdomains are derived from ceramide-rich ER exit sites and form contacts with the Golgi. Furthermore, Bro1 helps to concentrate the tethering and lipid transfer protein Tcb3, a homologue of human extended synaptotagmins, at these organelle contacts and contributes to cellular fitness when lipid metabolism is perturbed. These results indicate that specialised ER exit sites can be repurposed for contacting the Golgi directly and uncover ESCRTs as organisers of stress-inducible ER-Golgi contacts that help maintain cell homeostasis.

cell biology↗

bioRxiv2025

KCNQ1 regulates human neuronal development through mitochondrial and insulin signalling pathways

KCNQ1 encodes a voltage-gated potassium channel implicated in various peripheral and neurological disorders, yet its role during human neuronal development remains unclear. To investigate this, we generated KCNQ1 knockouts (KO) in human induced pluripotent stem cell lines and differentiated them into neural stem cells (NSCs) and cortical neurons. KCNQ1-deficient NSCs showed impaired neurite outgrowth, linked to reduced cell adhesion and disrupted neural cell adhesion molecule (NCAM) signalling. This phenotype was reproduced in wild-type and heterozygous lines by pharmacological KCNQ1 inhibition. Whole transcriptome, proteome, and follow-up analyses revealed mitochondrial dysfunction in KO NSCs, including reduced mitochondrial copy number and ATP synthase expression. Additionally, evidence was obtained for an impairment of insulin signalling in NSCs and neurons, with diminished insulin receptor gene expression and perturbation of key downstream signalling pathways (RAS-MAPK, PI3K-AKT). In neurons, KCNQ1 loss resulted in decreased synaptic activity and a more immature gene expression profile. Overall, our work reveals a novel role for KCNQ1 in human neurodevelopment by regulating cell adhesion, mitochondrial function, and insulin signalling. This work increases our understanding of KCNQ1 function in neurons and its contribution to neurological phenotypes observed in patients with KCNQ1-related diseases.

molecular biology↗

bioRxiv2025

Chromosome segregation in Escherichia coli involves DNA binding by the MinC-MinD complex

The Escherichia coli Min system, composed of the proteins MinC, MinD, and MinE, is crucial for directing septum formation at mid-cell. MinD has also been shown to bind DNA in a non-sequence-specific manner and to tether plasmid DNA to liposomes. A role for the Min system in chromosome segregation has been proposed, whereby repeated, transient membrane-tethering events mediated by MinD could help prevent backward movements of the duplicated chromosomes once entropic forces weaken. However, the contribution of the other Min proteins to DNA binding has remained unclear. Here, we demonstrate that DNA binding is strongly enhanced when MinD and MinC form a complex, while MinE and FtsZ (at high concentrations) interfere with this binding. We reveal a critical role for the linker connecting MinCs N- and C-terminal domains in both DNA binding and inhibition of FtsZ polymerization. E. coli strains expressing MinC linker variants from the native locus, in combination with the alpha subunit of HU tagged with GFP, display chromosomes that appear more spread throughout the cell. This phenotype could reflect reduced compaction, chromosome segregation defects, or a combination of both. These findings suggest a previously unrecognized role for the MinC linker in DNA binding and provide new insights into a potential physiological role of MinCD-DNA bnding in chromosome organization and/or dynamics.

microbiology↗

bioRxiv2022

The K+ exchange antiporter 3 senses the chloroplast energy status to synchronize photosynthesis

Plant photosynthesis contains two functional modules, the light-driven reactions in the thylakoid membrane and the carbon-fixing reactions in the chloroplast stroma. In nature, light availability for photosynthesis often undergoes massive and rapid fluctuations. Efficient and productive use of such variable light supply requires an instant crosstalk and rapid synchronization of both functional modules. Here, we show that this communication involves the stromal exposed regulatory C-terminus (RCT) of the thylakoid K+-exchange antiporter KEA3. RCT-mediated control of KEA3 contributes to the balance between light capture and photoprotection. By combining in silico, in vitro, and in vivo approaches, we demonstrate that the RCT senses the energy state of the chloroplast in form of both, phosphorylation and redox potential, in a pH-dependent manner and regulates KEA3 activity in response. Together our data pinpoint a regulatory feedback loop by which the stromal energy state orchestrates light capture and photoprotection via KEA3.

plant biology↗

bioRxiv2022

Genomic instability in patients with sex determination defects and germ cell cancer

The ability to transmit genetic information through generations depends on preservation of genome integrity. Genetic abnormalities affect cell differentiation, causing tissue specification defects and cancer. We addressed genomic instability in individuals with Differences of Sex Development (DSD), characterized by gonadal dysgenesis, infertility, high susceptibility for different types of cancer, especially Germ Cell Tumors (GCT), and in men with testicular GCTs. Whole proteome analysis of leukocytes, supported by specific gene expression assessment, and dysgenic gonads characterization, uncovered DNA damage phenotypes with altered innate immune response and autophagy. Further examination of DNA damage response revealed a reliance on deltaTP53, which was compromised by mutations in the transactivation domain in DSD-patients with GCT. Accordingly, drug-induced rescue of DNA damage was achieved by autophagy inhibition but not by stabilization of TP53 in DSD-patients blood in vitro. This study elucidates possibilities for prophylactic treatments of DSD patients as well as new diagnostic approaches of GCT. TeaserDNA damage phenotypes accompany aneuploidy of sex chromosomes and link to infertility and high propensity to germ cell tumor development.

genetics↗

bioRxiv2022

A novel role of 3,5-cAMP in the regulation of actin cytoskeleton in Arabidopsis.

The role of cyclic adenosine monophosphate (3,5-cAMP) in plants is not well understood, and here, we report a novel role of 3,5-cAMP in regulating the actin cytoskeleton. The 3,5-cAMP treatment affects the thermal stability of 51 proteins, including a vegetative actin isoform, ACTIN2. Consistent with the above results, the increase in 3,5-cAMP levels, obtained either by feeding or by chemical modulation of 3,5-cAMP metabolism, is sufficient to partially rescue the short hypocotyl phenotype of the actin2 actin7 mutant, severely compromised in actin level. No such complementation was measured for a positional isomer of 3,5-cAMP, 2,3-cAMP, attesting to the specificity of 3,5-cAMP treatment. Moreover, supplementation of 3,5-cAMP partly counters the activity of an actin-depolymerizing drug latrunculin B. In vitro characterization of the 3,5-cAMP - actin interaction argues against the direct binding. Instead, based on the proteomics characterization of the act2act7 mutant supplemented with 3,5-cAMP, we hypothesize that 3,5-cAMP affects cytoskeleton dynamic by modulation of calcium signaling, and actin binding proteins.

plant biology↗

bioRxiv2021

SLIMP: Supervised learning of metabolite-protein interactions from co-fractionation mass spectrometry data

Metabolite-protein interactions affect and shape diverse cellular processes. Yet, despite advances, approaches for identifying metabolite-protein interactions at a genome-wide scale are lacking. Here we present an approach termed SLIMP that predicts metabolite-protein interactions using supervised machine learning on features engineered from metabolic and proteomic profiles from a co-fractionation mass spectrometry-based technique. By applying SLIMP with gold standards, assembled from public databases, along with metabolic and proteomic data sets from multiple conditions and growth stages we predicted over 9,000 and 20,000 metabolite-protein interactions for Saccharomyces cerevisiae and Arabidopsis thaliana, respectively. Extensive comparative analyses corroborated the quality of the predictions from SLIMP with respect to widely-used performance measures (e.g. F1-score exceeding 0.8). SLIMP predicted novel targets of 2, 3 cyclic nucleotides and dipeptides, which we analysed comparatively between the two organisms. Finally, predicted interactions for the dipeptide Tyr-Asp in Arabidopsis and the dipeptide Ser-Leu in yeast were independently validated, opening the possibility for future applications of supervised machine learning approaches in this area of systems biology.

systems biology↗

bioRxiv2020

Hello darkness, my old friend: 3-Ketoacyl-Coenzyme A Synthase4 is a branch point in the regulation of triacylglycerol synthesis in Arabidopsis by re-channeling fatty acids under carbon starvation

Due to their sessile lifestyle, plants have evolved unique mechanisms to deal with environmental challenges. Under stress, plant lipids are important as alternative sources of carbon and energy when sugars or starch are limited. Here, we applied combined heat and darkness and extended darkness to a panel of [~] 300 Arabidopsis accessions to study lipid remodeling under carbon starvation. Natural allelic variation at 3-KETOACYL-COENZYME A SYNTHASE4 (KCS4), a gene encoding for an enzyme involved in very long chain fatty-acid (VLCFA) synthesis, underlies a differential accumulation of polyunsaturated triacylglycerols (puTAGs) under stress. Ectopic expression in yeast and plants proved that KCS4 is a functional enzyme localized in the ER with specificity for C22 and C24 saturated acyl-CoA. Allelic mutants and transient overexpression in planta revealed the differential role of KCS4 alleles in VLCFA synthesis and wax coverage, puTAG accumulation and biomass. Moreover, the region harboring KCS4 is under high selective pressure and allelic variation at KCS4 correlated with environmental parameters from the locales of Arabidopsis accessions. Our results provide evidence that KCS4 plays a decisive role in the subsequent fate of fatty acids released from chloroplast-membrane lipids under carbon starvation. This work sheds light on both plant response mechanisms and the evolutionary events shaping the lipidome under carbon starvation. One sentence summaryNatural variation at KCS4 underlies a differential accumulation of polyunsaturated triacylglycerols under carbon starvation, by acting as a regulatory branch point in the fate of fatty acids.

genetics↗