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Biology subjects

Grishchenko, N.

Publications and source records attributed to Grishchenko, N..

2 recordsLinked to original sources

Toggle-Untoggle: A cell segmentation tool with an interactive user verification interface.

Accurate cell segmentation is an essential step in the quantitative analysis of fluorescence microscopy images. Pre-trained deep learning models for automatic cell segmentation, such as Cellpose, offer strong performance across a variety of biological datasets but may still introduce segmentation errors. While training custom models can improve accuracy, it often requires programming expertise and significant time, limiting the accessibility of automatic cell segmentation for many wet lab researchers. To address this gap, we developed "Toggle-Untoggle", a desktop application that combines automated segmentation using the Cellpose "cyto3" model with a user-friendly graphical interface for intuitive segmentation quality control. Our app allows users to refine results by interactively toggling individual segmented cells on or off without the need to manually edit segmentation masks, and to export morphological data and cell outlines for downstream analysis. Here we demonstrate the utility of "Toggle-Untoggle" in enabling accurate, efficient single-cell analysis on real-world fluorescence microscopy data, with no coding skills required.

bioinformatics↗

Vacuolar pH regulates clathrin-mediated endocytosis through TORC1 signaling during yeast replicative aging

Clathrin-mediated endocytosis (CME) is a critical cellular process that regulates nutrient uptake, membrane composition and signalling. While cellular aging is associated with functional changes across many cellular components contributing to the collective decline in cellular function, little is known about how it affects CME. Here we show that CME dynamics are significantly altered during replicative aging in budding yeast, with older cells having slower assembly of early and coat CME modules, resulting in longer endocytic turnover and reduced cargo internalization. This change in CME dynamics is mother cell-specific and is not observed in daughter cells. We identified vacuolar pH, a key driver of aging phenotypes in budding yeast, as a central player in this modulation of CME dynamics during aging. Perturbing vacuolar pH in young cells mimics aging-like CME dynamics, while maintaining an acidic vacuolar pH in aging cells preserves CME dynamics typical of young cells. Finally, we demonstrate that the vacuolar pH effect on CME is regulated through TORC1 via the effector kinase Npr1. These findings establish vacuolar pH as a critical regulator of CME during cellular aging, and strengthen its role in the overall cellular aging process in budding yeast.

cell biology↗