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Biology subjects

Mor, E.

Publications and source records attributed to Mor, E..

5 recordsLinked to original sources

SeverYX: An ensemble framework for robust variant severity classification

Accurate interpretation of genetic variants in clinical genomics depends on reconciling multiple computational predictors that often disagree or provide incomplete evidence. We present SeverYX, a transparent, rule-based ensemble framework that consolidates conservation, splicing, and functional-impact predictors into a three-tier severity classification ('High', 'Medium', 'Low') through an effect-aware decision architecture. We benchmarked SeverYX against a curated ClinVar dataset of 270,208 MANE-transcript variants (86,161 pathogenic/likely pathogenic, 184,047 benign/likely benign), stratified by molecular consequence, review status, and haploinsufficiency. The baseline configuration achieved 97.6% concordance with ClinVar; at a fixed High cut, 90.0% of pathogenic and 2.0% of benign variants were assigned High. Concordance was highest for loss-of-function variants and lowest for non-coding and unclassified pathogenic variants, reflecting known gaps in current predictive tools. Systematic threshold optimization, combined with the addition of AlphaMissense and REVEL as missense predictors, raised overall concordance to 98.7%, reduced the benign High rate to 0.4% (at a cost of pathogenic High sensitivity falling to 88.3%), and improved the Matthews correlation coefficient from 0.895 to 0.908. These results show that SeverYX offers a transparent, reproducible and extensible approach for consolidating heterogeneous variant-effect evidence into clinically interpretable severity calls, and a scalable path for incorporating future predictive models into genomic interpretation workflows.

genetics↗

A precise balance of TETRASPANIN1/TORNADO2 activity is required for vascular proliferation and ground tissue patterning in Arabidopsis

The molecular mechanisms guiding oriented cell divisions in the root vascular tissues of Arabidopsis thaliana are still poorly characterized. By overlapping bulk and single-cell transcriptomic datasets, we unveiled TETRASPANIN1 (TET1) as a putative regulator in this process. TET1 is expressed in root vascular cells and loss-of-function mutants contain fewer vascular cells files. We further generated and characterized a CRISPR deletion mutant and show, unlike previously described mutants, that the full knock out is additionally missing endodermal cells in a stochastic way. Finally, we show that HA-tagged versions of TET1 are functional in contrast to fluorescent TET1 translational fusions. Immunostaining using HA-TET1 lines complementing the mutant phenotype revealed a dual plasma membrane and intracellular localization in the root vasculature and a polar membrane localization in young cortex, endodermal and initial cells. Taken together, we show that TET1 is involved in both vascular proliferation and ground tissue patterning. Our initial results pave the way for future work into deciphering its precise mode of action. Summary statementThis study reveals a novel role of tetraspanin TET1/TRN2 in root vascular development and ground tissue patterning in the model plant Arabidopsis thaliana.

plant biology↗

bHLH heterodimer complex variations shape meristems in Arabidopsis thaliana by affecting target gene specificity

The main regions of cell proliferation in plants are the root and shoot apical meristems during primary growth and the vascular cambia as lateral meristems during secondary thickening. A number of unique regulators have been described in each of these meristems, suggesting that these different meristems might have independently evolved dedicated transcriptional networks to balance cell proliferation. Here, we show that the basic Helix Loop Helix (bHLH) transcription factor complexes formed by TARGET OF MONOPTEROS5 (TMO5), LONESOME HIGHWAY (LHW) and their close homologs are broadly expressed throughout plant development and operate as general regulators of cell proliferation in all meristems. Yet, genetic and expression analyses indicate that these complexes have specific functions in distinct meristems mediated by heterodimer complex variations between members of the TMO5 and LHW subclades. We determine that this is primarily due to their expression domains limiting the possible combinations of heterodimer complexes within a certain meristem, and to a certain extent to the absence of some members in a given meristem. We further demonstrate target gene specificity for heterodimer complexes, suggesting that spatial differences in transcriptional responses through heterodimer diversification allow a common bHLH heterodimer complex module to contribute to the control of cell proliferation in multiple meristems.

developmental biology↗

The TPLATE subunit is essential for structural assembly of the endocytic TSET complex

All eukaryotic cells rely on endocytosis to regulate the plasma membrane proteome and lipidome. Most eukaryotic groups, with the exception of fungi and animals, have retained the evolutionary ancient TSET complex as a regulator of endocytosis. Despite the presence of similar building blocks in TSET, compared to other coatomer complexes, structural insight into this adaptor complex is lacking. Here, we elucidate the molecular architecture of the octameric plant TSET complex (TPLATE complex/TPC) using an integrative structural approach. This allowed us to describe a plant-specific connection between the TML subunit and the AtEH/Pan1 proteins and show a direct interaction between the complex and the plasma membrane without the need for any additional protein factors. Furthermore, we identify the appendage of TPLATE as crucial for complex assembly. Structural elucidation of this ancient adaptor complex vastly advances our functional as well as evolutionary insight into the process of endocytosis. Graphical abstract O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

cell biology↗

Evolution of vascular plants through redeployment of ancient developmental regulators

Vascular plants provide most of the biomass, food and feed on earth; yet the molecular innovations that led to the evolution of their conductive tissues are unknown. Here, we reveal the evolutionary trajectory for the heterodimeric TMO5/LHW transcription factor complex, which is rate-limiting for vascular cell proliferation in Arabidopsis thaliana. Both regulators have origins predating vascular tissue emergence, and even terrestrialization. We further show that TMO5 evolved its modern function, including dimerization with LHW, at the origin of land plants. A second innovation in LHW, coinciding with vascular plant emergence, conditioned obligate heterodimerization and generated the critical function in vascular development. In summary, our results suggest that division potential of vascular cells may have been a major driver in the evolution of vascular plants.

plant biology↗