Biology subjects

Juric, V.

Publications and source records attributed to Juric, V..

5 recordsLinked to original sources

bioRxiv2026

Beyond the surface: plasmalogens are dispensable for retinal integrity and fertility in the mouse

Ether lipids and their subclass, the plasmalogens, are critical regulators of membrane organization, signaling, and stress responses in multiple tissues. Inborn errors in their anabolism cause severe multi-organ diseases such as Rhizomelic Chondrodysplasia Punctata and related peroxisomal disorders. The Gnpat knockout mouse model, characterized by total ether lipid deficiency, recapitulates key features of this disorder, including dense bilateral cataracts, microphthalmia, and infertility, but the specific contribution of different subclasses like plasmalogens remains elusive. The recent identification of the Peds1 gene allows dissecting the impact of selective plasmalogen deficiency with retention of plasmanyl lipids, another ether lipid subgroup. Here, we performed the first side-by-side comparison of Gnpat and Peds1 knockout in mice on a matched genetic background (C57BL/6 x CD1). In contrast to the situation in Gnpat knockout mice, plasmanyl lipids in Peds1 knockout mice were sufficient to prevent cataract formation and maintain normal ocular structures, despite marked shifts in the ocular phospholipidome. Also, fertility and reproductive function were found to be preserved in Peds1 knockout mice. Our data demonstrate that plasmanyl lipids can partially protect against the severe phenotypes observed in mouse models of total ether lipid deficiency; notably, the ocular and reproductive phenotypes were plasmalogen-independent, indicating that loss of the vinyl ether double bond is not the key determinant of all symptoms in human and murine ether lipid deficiency and can at least partly be compensated by plasmanyl lipids. HighlightsO_LIIn mice, total ether lipid deficiency causes cataracts and infertility. C_LIO_LIThe role of plasmalogens in these phenomena remains unclear. C_LIO_LITwo PEDS1-deficient patients were reported, but cataracts were observed in only one case. C_LIO_LIPeds1-deficient mice have no cataracts or ocular abnormalities. C_LIO_LIMice with a deletion of Peds1 display normal fertility rates. C_LI

biochemistry↗

bioRxiv2025

Yeast MoClo secretion and surface display toolkit 2.0: improvements and applications for analysis of protein-protein interactions and whole-cell biocatalysis

Saccharomyces cerevisiae is an invaluable model organism for both fundamental biological research and biotechnological applications including recombinant protein production as well as protein and metabolic engineering. We previously developed a modular cloning (MoClo) based toolkit for S. cerevisiae that facilitates rapid optimization of signal peptides and anchor proteins for efficient secretion and/or surface display of heterologous proteins of interest. Here we describe further improvements and applications of this yeast secretion and display (YSD) toolkit. New parts encoding anchor proteins based on N-terminal fusion to a truncated Aga1 and C-terminal fusion to Aga2, each with three possible epitope tag options, are described. We also added parts that facilitate high throughput detection of secreted proteins of interest through GFP fluorescence complementation and parts encoding "secretion boosting" yeast proteins, whose overexpression has previously been reported to enhance secretion of heterologous proteins. In addition, two surface display applications of the toolkit are showcased. We demonstrate that yeast surface display of an anti-GFP nanobody allows cost-effective evaluation of the interactions of GFP-tagged proteins of interest, either by flow cytometry or yeast-based co-immunoprecipitation. In addition, using yeast cells as whole-cell catalysts, we show that co-display of the poly(ethylene terephthalate) (PET) degrading enzyme leaf-branch compost cutinase with hydrophobin1 enhances the breakdown of PET plastic, while triple co-display of these proteins with MHETase causes complete conversion of the intermediary monohydroxyLethyl-terephthalate (MHET) to terephthalic acid. The diverse applications described herein demonstrate the broad applications of the updated MoClo YSD toolkit 2.0 in both synthetic biology and other research fields.

synthetic biology↗

bioRxiv2025

Biochemical signatures from dried blood spots in untargeted metabolics are influenced by matrix effects

Dried blood spots (DBS) represent a convenient clinical sample material, offering low infection risk, easy transport, and long-term metabolite stability. However, applying samples such as whole blood, serum or plasma onto filter paper introduces an additional matrix, potentially affecting metabolite extraction. Here, we compare metabolite recovery from liquid samples and their filter paper analogue using both targeted (acylcarnitines, amino acids) and untargeted metabolomics. Significant matrix effects were observed for some compounds, especially for dicarboxylic acylcarnitines (C3DC-C6DC) and specific amino acids (cystine, cystathionine). We did not identify specific metabolite characteristics that may predicted altered recovery. In a cohort of 229 authentic DBS samples -- including patients diagnosed with inherited metabolic disorders, obesity or under a ketogenic diet -- untargeted profiling combined with random-forest machine learning led to an effective stratification. Notably, C4DC, despite strong matrix effects, was ranked in the top ten variables of this random-forest model. With adequate validation, DBS can be safely used for diagnostic purposes despite possible matrix effects, but care must be taken in the comparison of values obtained when different sample materials are used.

biochemistry↗

bioRxiv2024

Mitochondrial cardiolipin metabolism controlled by tafazzin enables ferroptosis

Mitochondria are important producers of reactive oxygen species, which are involved in triggering ferroptosis, a lipid peroxidation driven form of cell death. Paradoxically, in the rare inherited metabolic disease Barth Syndrome, we discovered a protection from erastin-induced ferroptosis, despite intrinsically elevated mitochondrial ROS levels. The affected transacylase tafazzin, which is mutated in Barth Syndrome, is pivotal for remodeling of the dimeric phospholipid cardiolipin. They unique to mitochondria and essential for shaping their membrane functionalities. We investigated which downstream effects of the pathogenic membrane alterations are responsible for the protective effect against ferroptosis. We found that while iron metabolism, the unsaturation of membrane lipids, and the metabolic activity of the cells were modifying factors, they were not causal. However, we observed that cardiolipin abnormalities are not limited to impair only inner, but also outer mitochondrial membrane protein complexes. Specifically, they impact abundance and oligomerization of voltage-dependent anion channels (VDAC) in response to oxidative stress. We found that tafazzin deficiency via alteration of cardiolipins affects VDAC functionality, thereby modulating small molecule transport and signaling between mitochondria and the remaining cell. This is in line with a reduction of mitochondria-associated membranes (MAM) sites that are formed through VDACs and trapping ROS in mitochondria where they are unable to contribute to ferroptosis. These findings demonstrate that the mitochondrial membrane architecture impacting on subcellular small molecule distribution crucially impact on the manifestation of cell fate decisions, including ferroptosis.

molecular biology↗

bioRxiv2023

A yeast modular cloning (MoClo) toolkit expansion for optimization of heterologous protein secretion and surface display in Saccharomyces cerevisiae.

Saccharomyces cerevisiae is an attractive host for expression of secreted proteins in a biotechnology context. Unfortunately, many heterologous proteins fail to enter, or efficiently progress through, the secretory pathway, resulting in poor yields. Similarly, yeast surface display has become a widely used technique in protein engineering but achieving sufficient levels of surface expression of recombinant proteins is often challenging. Signal peptides (SPs) and translational fusion partners (TFPs) can be used to direct heterologous proteins through the yeast secretory pathway, however, selection of the optimal secretion promoting sequence is largely a process of trial and error. The yeast modular cloning (MoClo) toolkit utilises Type IIS restriction enzymes to facilitate efficient assembly of expression vectors from standardized parts. We have expanded this toolkit to enable the efficient incorporation of a panel of sixteen well-characterized SPs and TFPs and five surface display anchor proteins into S. cerevisiae expression cassettes. The secretion promoting signals were validated using five different proteins of interest. Comparison of intracellular and secreted protein levels revealed the optimal secretion promoting sequence for each individual protein. Large, protein of interest-specific variations in secretion efficiency were observed. SP sequences were also used with the five surface display anchors and the combination of SP and anchor protein proved critical for efficient surface display. These observations highlight the value of the described panel of MoClo compatible parts to allow facile screening of SPs, TFPs and anchor proteins for optimal secretion and/or surface display of a given protein of interest in S. cerevisiae. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=100 SRC="FIGDIR/small/570949v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@14791d8org.highwire.dtl.DTLVardef@1b80f06org.highwire.dtl.DTLVardef@e29365org.highwire.dtl.DTLVardef@13aec24_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗