Biology subjects

Terpstra, H. M.

Publications and source records attributed to Terpstra, H. M..

3 recordsLinked to original sources

bioRxiv2026

Cell cycle dynamics of redox state and lipid metabolism in S. cerevisiae, S. pombe and murine leukaemia cells

Coordination of metabolism, cell growth and cell division is essential to life. Recent single-cell measurements in S. cerevisiae have shown that metabolic processes and the cellular redox state are dynamic along the cell cycle. However, it is unknown whether similar metabolic oscillations also occur in other organisms. Until now, the dynamics of metabolism in other eukaryotes have predominantly been studied in cell cycle synchronised populations. Since cell cycle synchronisation methods can perturb metabolism, they may also introduce artefacts in the recorded dynamics. Here, we performed time-lapse microscopy analyses of exponentially growing single cells of the budding yeast S. cerevisiae, the fission yeast S. pombe and murine leukaemia L1210 cells. Measuring the NAD(P)H autofluorescence and the cell surface area growth rate in unsynchronised cells, we discovered oscillations along the cell cycle of the cellular redox state and lipid metabolism, respectively. Thus, our work shows that metabolism is dynamic along the cell cycle of these three evolutionarily distant eukaryotic organisms. This finding suggests that such metabolic oscillations could be a conserved characteristic among eukaryotes.

cell biology↗

bioRxiv2025

Lipid droplet dynamics during the budding yeast cell cycle influence the timing of cell cycle START

Recent work has revealed that metabolism is dynamic over the budding yeast cell cycle, showing that the NAD(P)H autofluorescence oscillates, and protein and lipid biosynthesis are dynamic. Dynamic storage and liquidation of neutral lipids over the cell cycle could contribute to these metabolic dynamics. However, the dynamics of neutral lipids over the cell cycle are as yet unknown. To elucidate them, we established mNeonGreen-Tgl3 and Pln1-mNeonGreen as protein markers for lipid droplets (LDs) and determined LD dynamics during the cell cycle with single-cell time-lapse microscopy. We found oscillations in the LD number over the cell cycle, with a notable trough around START. Deletion of the genes responsible for either the synthesis of triacylglycerol (TAG) or its mobilisation from LDs lowered LD numbers and abolished the oscillation in LD number. Moreover, in these deletion mutants, we found START to be delayed, suggesting that the mobilisation of TAG from LDs is required for its timely occurrence. The influence of LD dynamics on the timing of START emphasises that research studying cell cycle commitment should consider storage lipid metabolism as a potential contributor to cell cycle START.

cell biology↗

bioRxiv2025

Detecting Nuclear Pore Complex assembly in living cells

The formation of nuclear pore complexes (NPCs) -- vital gateways regulating nuclear-cytoplasmic transport -- is a highly orchestrated process requiring the integration of hundreds of nucleoporins into the nuclear envelope. A major challenge in studying this assembly process in living cells has been the difficulty to distinguish newly forming NPCs from their mature counterparts. Here, we present a powerful nanobody-based approach that overcomes this limitation. We demonstrate that a nanobody targeting the nucleoporin Nic96 from Saccharomyces cerevisiae selectively binds newly synthesized Nic96 subcomplexes prior to its incorporation into NPCs in vivo. Importantly, nanobody-bound Nic96 is incorporated in NPCs, and expression of the nanobody does not disrupt nuclear transport, cell growth, or lifespan, nor does it show genetic interactions with known NPC assembly surveillance pathways -- making it an ideal, non-perturbing tool to study NPC biogenesis in yeast. Illustrating the use of the Nic96 nanobody we report novel aspects of the early stages of assembly, including co-recruitment of Kap121 and VHH[Nic96] to putative assembly sites. In addition, we show local enrichment of newly synthesized nucleoporins on nuclear envelope proximal lipid droplets, including a specific subset of Pdr16- and Ldo16-positive lipid droplets near the nucleus-vacuole junction. When NPC assembly is delayed, association of Nic96 subcomplexes with lipid droplets increases. These findings illustrate how the strategy to pulse-label newly forming NPCs opens new avenues for dissecting the spatiotemporal regulation of NPC assembly and misassembly.

cell biology↗