A newly identified three-domain C-type lectin associated with blood feeding in the tick Ixodes ricinus

Kotsarenko, K.; Hajdusek, O.; Rievajova, M.; Bezdekova, K.; Vechtova, P.; Malinovska, L.; Paulenova, E.; Houser, J.; Sterba, J.; Grubhoffer, L.; Wimmerova, M.

doi:10.64898/2026.01.07.698205

bioRxiv · 10.64898/2026.01.07.698205

A newly identified three-domain C-type lectin associated with blood feeding in the tick Ixodes ricinus

Kotsarenko, K.·Hajdusek, O.·Rievajova, M.·Bezdekova, K.·Vechtova, P.·Malinovska, L.·Paulenova, E.·Houser, J.·Sterba, J.·Grubhoffer, L.·Wimmerova, M.

View original source ↗Export metadata ↓

Abstract

Ixodes ricinus ticks are widely distributed throughout Europe and represent major vectors of tick-borne encephalitis virus and the Lyme borreliosis agent Borrelia burgdorferi sensu lato. In invertebrates, C-type lectins are commonly associated with innate immune functions, and several such lectins have been predicted in I. ricinus. Given the limited knowledge of lectin function in ticks, we characterized three carbohydrate-recognition domains (CRDs) of a novel C-type lectin identified in the I. ricinus transcriptome (IrCLec). The tertiary structures of CRD1, CRD2, and CRD3, predicted using the AlphaFold 3 program, corresponded to the typical structure of C-type lectins. Conserved carbohydrate-binding motifs were identified in CRD3, whereas non-canonical motifs were present in CRD1 and CRD2. Recombinant His-tagged CRDs were produced and analysed for carbohydrate-binding activity. Glycan array analysis revealed binding of all three domains to selected glycans, while hemagglutination assays demonstrated pronounced binding activity of CRD1 and CRD2 toward human erythrocyte antigens of blood groups A, B, and O. IrCLec expression was highest in the tick midgut and also detected in hemocytes, with expression levels increasing after blood feeding. RNAi-mediated silencing of IrCLec impaired blood feeding efficiency in tick nymphs. Together, these results indicate that IrCLec plays an important role in blood feeding and may additionally participate in lectin-mediated host-pathogen or host-blood component interactions.

Source connections

Published article ↗

Explore related subjects

biochemistry Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Kotsarenko, K., Hajdusek, O., Rievajova, M., Bezdekova, K., Vechtova, P., Malinovska, L., Paulenova, E., Houser, J., Sterba, J., Grubhoffer, L., Wimmerova, M.. 2026-01-08. A newly identified three-domain C-type lectin associated with blood feeding in the tick Ixodes ricinus. https://doi.org/10.64898/2026.01.07.698205

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

KEEP EXPLORING

Related preprints

bioRxiv2026

Deep reinforcement learning-driven discovery of a MsbA-targeted small-molecule antibiotic for the treatment of Acinetobacter baumannii infection

Antibiotics with new mechanisms are highly pursued to address the threat of infections caused by drug-resistant Gram-negative bacteria. Targeting MsbA, a key protein of the lipopolysaccharide biosynthesis pathway, represents a promising strategy to discover new classes of antibiotics. However, currently available MsbA-targeted molecules either lack sufficient potency or have unfavorable properties, necessitating expansion of chemical space. In this study, we chose the most promising cerastecin Cpd 4 as the template, and used two Artificial Intelligence (AI)-based tools, i.e. Link-INVENT and AutoMolDesigner for molecular design, performed chemical derivatization and antibacterial activity evaluation, which led to the discovery of Y-11 (MIC for A. baumannii: 0.5 g/mL). Encouragingly, Y-11 showed equivalent potency to Cpd4 for carbapenem-resistant A. baumannii, and less cytotoxicity and hemolysis as well as lower spontaneous resistance frequency. In vivo efficacy study demonstrated that Y-11 could effectively reduce bacterial loads in the mice infected by A. baumannii. The following mechanism study including molecular dynamics simulation, biochemical assay, and transmission electron microscope (TEM) analysis suggested that Y-11 inhibited the transport of lipooligosaccharide and impaired the formation of outer membrane, probably by competitively binding to the substrate binding site of MsbA and modulating ATPase activity. Taken together, we have discovered a MsbA-targeted small molecule Y-11 via AI-driven drug design, which provides a foundation for future antibiotic development.

biochemistry↗

bioRxiv2026

Dynamic architecture of the Rixosome reveals mechanism of activation and ITS2 processing

Eukaryotic ribosome assembly requires the coordinated processing and extensive remodeling of pre-rRNAs. During late nuclear maturation of the 60S subunit, sequential removal of the internal transcribed spacer 2 (ITS2) is initiated by endonucleolytic cleavage at site C2 by the conserved Las1 nuclease. Las1 acts together with the kinase Grc3 and the Rix1 complex to form the Rixosome, which also functions in transcriptional regulation. However, the assembly of the Rixosome, its recruitment to pre-ribosomes, and its activation for ITS2 cleavage remain unclear. Here, we present cryo-EM structures of the human LAS1 complex, two structures of the isolated Rixosome and nine transition states of Rix1-bound pre-60S particles from Schizosaccharomyces pombe. These structures reveal a dynamic Rixosome architecture in which the heterotetrameric Las1 complex engages one or two copies of the Rix1 complex. Rix1 binding is highly flexible in the human Rixosome but rigid in the yeast complex. The isolated yeast Rixosome remains inactive, but binding to the pre-60S particle triggers a structural rearrangement that allows for substrate engagement and activation of the nuclease. Together, our results define the dynamic architecture of the Rixosome and provide a structural framework for ITS2 processing during nuclear maturation of the eukaryotic 60S ribosomal subunit.

biochemistry↗

bioRxiv2026

SGFP-Grid Split GFP Graphene Grids

Affinity graphene grids provide a promising approach for selective protein capture in cryo-EM. Here, we introduce a split-GFP graphene grid platform(SGFP-G), in which graphene-conjugated GFP 1-10 selectively captures GFP11 tagged proteins from low concentration samples or cell lysates. This platform enables rapid assessment of target protein enrichment and particle distribution before vitrification via fluorescence imaging, while the grid design positions captured proteins away from the graphene surface and air-water interface. We also introduce a unique strategy to minimize nonspecific protein adsorption, thereby improving the selective enrichment of target proteins on this grid. Using GFP11-tagged apoferritin, we demonstrate fluorescence guided protein capture and obtain a 2.58 [A] cryoEM reconstruction, establishing SGFP-G as an affinity grid platform for high resolution structural studies with reduced sample requirements.

biochemistry↗