Biology subjects

Kurosu, M.

Publications and source records attributed to Kurosu, M..

3 recordsLinked to original sources

bioRxiv2026

Rationally Engineered, Chemically Stable Tunicamycin Analogues Decouple DPAGT1 Inhibition from Non-Selective Toxicity

Tunicamycins are potent inhibitors of dolichyl-phosphate N-acetylglucosamine phosphotransferase (DPAGT1) but are unsuitable for therapeutic development due to non-selective cytotoxicity, acid-labile glycosidic linkages, and poor physicochemical properties. Although prior structural modifications reduced the promiscuous toxicity of tunicamycins, the intrinsic 11'-{beta}-1''- trehalose-type glycosidic linkage remains chemically unstable, limiting biological durability. Here, we report a rationally engineered scaffold-stabilization strategy in which the acid-labile linkage is replaced with a chemically robust cyclitol framework, enabling the concise synthesis of chemically stable and water-soluble tunicamycin analogues in only 12 synthetic steps. From this platform, TM-Cy-TBPA (4) was identified as a lead DPAGT1 inhibitor that potently suppresses the proliferation of breast cancer cells by inducing G2-phase arrest followed by apoptosis, while exhibiting minimal cytotoxicity toward nontransformed cells. The compound shows improved solubility, and favorable pharmacokinetic exposure. These results establish tunicamycin cyclitol analogues as a structurally distinct class of selective DPAGT1-targeted anticancer agents and demonstrate that stabilization of the glycosidic linkage is an effective strategy for enhancing pharmacological selectivity, improving in vivo performance, and simplifying the synthetic route.

biochemistry↗

bioRxiv2025

Structures of bacterial and human phosphoglycosyltransferases bound to a common inhibitor inform selective therapeutics

Glycoconjugates facilitate myriad biological processes, including cell-cell recognition and immune response, and they are generated by enzymes that transfer glycans. The orthologs MraY and DPAGT1 are dimeric phosphoglycosyltransferases involved in oligosaccharide biosynthesis for either bacterial peptidoglycan or eukaryotic N-linked glycans, respectively. Both enzymes play central regulatory roles, making them attractive targets for antibacterial and anticancer therapies. In our prior studies, a muraymycin A1-derived inhibitor termed APPB (aminouridyl phenoxypiperidinbenzyl butanamide) was developed. It exhibits sub-100 nM IC50 values against both MraY and DPAGT1 and has demonstrated efficacy against DPAGT1-dependent cancers, making it an excellent starting point for next-generation small molecules. To guide inhibitor development, we determined cryo-EM structures of APPB bound to MraY or DPAGT1 at 2.9 [A] resolution using single-particle analysis. The structures reveal that APPB, composed of a nucleoside, a central amide, and a lipid-mimetic, adopts two conformations in each protein, which correlate with local hydrogen-bonding contacts of the central amide carbonyl. Examination of the amide carbonyl environments guides conformer selection for future DPAGT1-targeting anticancer agents. Further, comparisons of APPB-bound geometries and nucleoside interactions inform opportunities for antibacterial agents targeting MraY. Overall, our study provides design principles for MraY- or DPAGT1-specific drugs and motivates the utility of simultaneously characterizing inhibitor-bound orthologs for selective therapeutics.

biochemistry↗

bioRxiv2024

LAG-3 blockade reactivates the CD8+ T cell expansion program to re-expand contracted clones in the tumor

Effective cancer immunotherapy relies on the clonal proliferation and expansion of CD8+ T cells in the tumor1,2. However, our insights into clonal expansions are limited, owing to an inability to track the same clones in tumors over time. Here, we developed a multi-tumor mouse model system to track hundreds of expanding and contracting CD8+ T cell clones over multiple timepoints in tumors of the same individual. Through coupling of clonal expansion dynamics and single-cell RNA/TCR-seq data, we identified a transcriptomic signature in PD-1+Ly108+ precursor exhausted cells3,4 that strongly predicts rates of intratumoral clone expansion in mice and humans. We found that expression of the signature successfully stratifies melanoma patient outcomes to PD-1/PD-L1 blockade5,6. Downregulation of the signature precedes clone contraction - a phase in which clones contract but maintain revivable precursor exhausted cells in the tumor. LAG-3 blockade - an FDA-approved therapy whose effects on CD8+ T cell responses are currently unclear7, re-activates the expansion signature, re-expanding pre-existing clones, including previously contracted clones. These findings reveal how the study of clonal expansion dynamics provide a powerful pan-immunotherapy signature for monitoring immunotherapies, including PD-1/PD-L1 and LAG-3 blockade, with implications for their future development.

immunology↗