Biology subjects

Ware, T.

Publications and source records attributed to Ware, T..

4 recordsLinked to original sources

bioRxiv2026

Mapping ortholog-restricted ligandable cysteines in the wheat pathogen Zymoseptoria tritici

Zymoseptoria (Z.) tritici is the fungal phytopathogen responsible for Septoria tritici leaf blotch (STB), the main foliar disease of wheat. Fungicides mitigate crop loss caused by STB, but multidrug-resistant Z. tritici strains pose a major threat to the global food supply and underscore the need to identify new fungicidal targets. Here, we use activity-based protein profiling to generate a covalent ligandability map of Z. tritici, leading to the discovery of cysteines in a diverse set of essential proteins that are targeted by stereochemically defined, electrophilic small molecules (stereoprobes). We identify stereoprobes that display nucleotide-dependent reactivity with an ortholog-restricted cysteine in the GTPase SAR1, leading to accumulation of this protein and other COPII components at apparent ER exit sites and corresponding impairments in Z. tritici growth. Our findings thus expand the scope of ligandable, essential proteins in Z. tritici and illuminate opportunities to selectively target this destructive plant pathogen.

biochemistry↗

bioRxiv2025

In vivo validation of the palmitoylation cycle as a therapeutic target in NRAS-mutant cancer

Ras proteins are functionally dependent on one or more lipid modifications.1,2 The dynamic palmitoylation of N-Ras by DHHC palmitoyl acyltransferases and depalmitoylation by ABHD17 serine hydrolases is essential for the growth of NRAS-mutant acute myeloid leukemia (AML) cells.3-6 Here we show that ABD778, an in vivo-active ABHD17 inhibitor, selectively reduces the growth of NRAS-mutant AML and melanoma cell lines and is synergistic with the MEK inhibitor PD0325901 (PD901; mirdametinib). Mechanistically, ABD778 and PD901 induce deep and durable suppression of mitogen activated protein kinase (MAPK) pathway activation. Co-treatment extended the survival of mice transplanted with NrasG12D AMLs, which acquired by-pass mutations at relapse that conferred drug resistance and restored MAPK activation. ABD778 augmented the anti-leukemia activity of PI3 kinase, pan-Ras tri-complex, and FLT3 inhibitors, and restored gilteritinib sensitivity in a patient-derived xenograft model of FLT3 inhibitor resistance. These studies validate the palmitoylation cycle as a therapeutic target in NRAS-mutant cancers.

cancer biology↗

bioRxiv2022

TMEM164 is an acyltransferase that forms ferroptotic polyunsaturated ether phospholipids

Ferroptosis is an iron-dependent form of cell death driven by the oxidation of polyunsaturated (PUFA) phospholipids. Large-scale genetic screens have pointed to a specialized role for PUFA ether phospholipids (ePLs) in promoting ferroptosis. Our understanding of the enzymes involved in PUFA ePL production, however, remains incomplete. Here we show using a combination of pathway mining of genetic dependency maps, AlphaFold-guided structure predictions, and targeted lipidomics that the uncharacterized transmembrane protein TMEM164 - genetic ablation of which has been shown to protect cells from ferroptosis - is a cysteine active-center enzyme that selectively transfers C20:4 acyl chains from phosphatidylcholine to lyso-ePLs to furnish PUFA-ePLs. TMEM164-null cells show substantial reductions in PUFA-ePLs, but not PUFA ester phospholipids, supporting that the selective suppression of PUFA-ePLs is sufficient to protect cells from ferroptosis and designating TMEM164 as a key enzyme specifically responsible for regulating this class of lipids.

biochemistry↗

bioRxiv2022

Lysosomal alterations and decreased electrophysiological activity in CLN3 disease (966 bp deletion, E295K) patient-derived cortical neurons

CLN3 disease is a lysosomal storage disorder associated with fatal neurodegeneration that is caused by mutations in CLN3. Most individuals with CLN3 disease carry at least one allele with a 966 bp deletion in CLN3 which results in the deletion of exons 7 and 8. There is a need for more physiologically relevant human cell-based CLN3 disease models to better understand the cellular changes during the disease process. Using CRISPR/Cas9, we corrected the 966 bp deletion mutation in human induced pluripotent stem cells (iPSCs) of a compound heterozygous patient (CLN3 {Delta} 966 bp and E295K). The isogenic deletion-corrected and unedited CLN3 patient iPSCs were used for disease modeling. iPSC-derived neurons carrying this particular CLN3 mutation (CLN3 neurons) had lower functional activity as recorded using microelectrode arrays for most of the culture period. Proteomics analysis showed downregulation of proteins related to axon guidance and endocytosis at day in vitro (DIV) 14 and 42 in CLN3 neurons. This was accompanied by an increase in lysosomal-related proteins in CLN3 neurons. Western blot analysis revealed hyperglycosylation of the lysosomal marker, Lysosome Associated Membrane Protein 1 (LAMP1) in CLN3 neurons at DIV 14, 28 and 42, which was not apparent in control neurons. Ultrastructural analysis of CLN3 neurons showed numerous membrane-bound vacuoles containing diverse types of storage material, ranging from curvilinear deposits, multilamellar structures to osmiophilic deposits. Our findings suggest alterations in lysosomal function and neurodevelopment involving axon guidance and synaptic transmission in CLN3-deficient neuronal derivatives, which could be potential targets for therapy.

neuroscience↗