bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.08.07.743491

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

Raisova Stuchlikova, L.·Sadibolova, M.·Sterbova, K.·Slaninova, N.·Skalova, L.·Matouskova, P.·Lubbehusen, N.·Ruppert, T.·Luzarowski, M.
View original source ↗Export metadata ↓

Abstract

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.

Explore related subjects

molecular biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Raisova Stuchlikova, L., Sadibolova, M., Sterbova, K., Slaninova, N., Skalova, L., Matouskova, P., Lubbehusen, N., Ruppert, T., Luzarowski, M.. 2026-08-09. Protein expression of short-chain dehydrogenases/reductases and their inducibility by flubendazole in Haemonchus contortus. https://doi.org/10.64898/2026.08.07.743491

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

An ssRNA Phage Single-gene Lysis Protein Targeting MraY Reveals Convergent Evolution Across the RNA-DNA Phage Boundary

Small lytic phages of the ssRNA Leviviricetes and ssDNA Microviricetes achieve host lysis by expression of a single protein, designated as an Sgl protein. Four ssRNA Sgls have been shown to inhibit steps in peptidoglycan biosynthesis: three target MurJ, the Lipid II flippase, and one targets MurA, the committed step of the pathway. A fifth Sgl, the E protein of the canonical ssDNA microvirus {varphi}X174, inhibits MraY, which catalyzes the synthesis of the first lipid-linked intermediate. This inhibition requires SlyD, a cytoplasmic FKBP-type peptidyl-prolyl cis-trans isomerase. The Sgl of the Caulobacter ssRNA phage {varphi}Cb5 (Cebevirus halophobicum) has not been characterized. Here, we present physiological evidence that Sgl{varphi}Cb5 targets MraY. Moreover, we show that, despite the absence of detectable sequence similarity, Sgl{varphi}Cb5 shares several features with the {varphi}X174 E protein, including the distribution of hydrophobic and charged residues, a proposed N-out, C-in membrane topology, and retention of lytic activity in an Sgl{varphi}Cb5 -LacZ fusion. Furthermore, expression of the Caulobacter cytoplasmic FKBP-type peptidyl-prolyl cis-trans isomerase CC2799 enhances Sgl{varphi}Cb5 -mediated lysis in E. coli. These parallels between Sgl function in a DNA phage and an RNA phage either represent remarkably consonant convergent evolution or some evolutionary cross-over event for which there is currently no precedent.

molecular biology↗
bioRxiv2026

HERC1-mediated orphan subunit quality control maintains proteasome homeostasis and is disrupted in HERC1-associated neurodevelopmental disease

Biallelic hypomorphic variants in the E3 ubiquitin ligase HERC1 cause a neurological disorder clinically characterized by macrocephaly, dysmorphic facies, and psychomotor delay. Identifying the substrates of HERC1 is essential for understanding its biological functions and the mechanisms underlying disease-associated variants. To address this, we performed a quantitative proteomic analysis using biotinylated ubiquitin to identify HERC1 targets and examine their regulation in cells expressing HERC1 with or without ubiquitin ligase activity. This approach revealed a broad set of HERC1-dependent ubiquitylation substrates, including proteins from major multiprotein complexes such as the proteasome, the translation initiation machinery, and pathways involved in cell metabolism. Focusing on the proteasome, the most prominently represented complex, we identified several regulatory particle subunits, including PSMC6, PSME1, and PSME2. Specifically, within the 19S regulatory particle, we demonstrated that ubiquitylation of the PSMC6 subunit involves the formation of K48-linked polyubiquitin chains and depends on HERC1 activity. Other 19S subunits, such as PSMC2, PSMC4, and PSMC5, undergo a similar modification. Mechanistically, we show that HERC1 selectively recognizes unassembled subunits, promotes their ubiquitylation, and targets them for proteasomal degradation. Notably, in HERC1-deficient cells, disruption of this mechanism impaired proteasomal activity. At the disease level, quantitative proteomic analysis of the pathogenic HERC1 variant c.1448G>A (p.Gly483Glu) likewise identified altered ubiquitylation of proteasome subunits and components of the translation initiation machinery. Biochemical analyses further revealed impaired ubiquitylation of PSMC6 by the mutant HERC1 protein, associated with a loss of interaction between HERC1 and PSMC6. Together, these findings establish a link between HERC1-associated neurological disorders and defective ubiquitylation pathways. They elucidate the molecular mechanisms by which HERC1 regulates proteostasis and demonstrate how disruption of these processes contributes to disease pathogenesis, thereby highlighting potential avenues for therapeutic intervention.

molecular biology↗
bioRxiv2026

PKR inhibition prevents maladaptive responses to endoplasmic reticulum (ER) stress in early-onset dystonia DYT-PRKRA.

DYT-PRKRA is a rare, childhood-onset dystonia caused by mutations in the PRKRA gene, which encodes the protein PACT. PACT activates protein kinase R (PKR) in response to endoplasmic reticulum (ER) stress. In DYT-PRKRA patient cells, the PACT-PKR interaction is enhanced, increasing sensitivity to ER stress-induced apoptosis. The canonical protein kinase activated by ER stress is PKR-like endoplasmic reticulum kinase (PERK), which phosphorylates the subunit of eukaryotic translation initiation factor 2 (eIF2) to initiate the integrated stress response (ISR) and restore cellular homeostasis via the transcription factor ATF4. However, under persistent stress, ATF4 induces CHOP, shifting the adaptive response toward apoptosis. PKR, also activated by ER stress, phosphorylates eIF2, but its contribution to cellular homeostasis remains understudied. This work shows, for the first time, that PKR activation is essential for CHOP induction during ISR, directly linking enhanced apoptosis in DYT-PRKRA cells to prolonged PKR activation and heightened CHOP induction. Strikingly, a small-molecule PKR inhibitor effectively blocks CHOP expression and significantly decreases apoptosis in DYT-PRKRA cells, suggesting PKR inhibition as an effective therapeutic strategy for DYT-PRKRA.

molecular biology↗