Mathey, A. | Search bioRxiv

bioRxiv2026

Endosomal membrane state governs trafficking and cell migration under TFEB control

Transcription Factor EB (TFEB) regulates the biogenesis of lysosomes, which are acidic organelles of the endosomal network. While its role in cellular clearance is well established, the pleiotropic functions of TFEB across diverse cellular processes, as well as its activation in several cancer types, remain incompletely understood. Investigating TFEB in a bladder cancer model, we found that its depletion selectively impaired cell migration and adhesion. This phenotype was associated with the retention of the adhesion molecule integrin {beta}5 (ITG{beta}5), in central intracellular compartments identified as multivesicular bodies (MVBs) upon TFEB knockdown (KD). Mechanistically, TFEB regulated cellular lipid composition and membrane fluidity of acidic endosomes that controlled ITG{beta}5 trafficking. Remarkably, exogenous supplementation with a monounsaturated fatty acid (MUFA) that increased MVB membrane fluidity was sufficient to phenocopy the intracellular trapping of ITG{beta}5 in 2D culture and 3D tumoroids. We further showed that TFEB-dependent maintenance of MVB membrane fluidity relies on ESCRT-0 subcomplex, HGS/Hrs, which retains cholesterol at MVBs. Together, these findings reveal how transcriptional programs shape endosomal membrane states to control cargo trafficking and cell behavior.

cell biology↗

bioRxiv2025

The Q-Warg Pipeline: A Robust and Versatile Workflow for Quantitative Analysis of Protoplast Culture Conditions

Single cells offer a simplified model for investigating complex mechanisms such as cell-cell adhesion. Protoplasts, plant cells without cell walls (CWs), have been instrumental in plant research, industrial applications, and breeding. However, due to the absence of a CW, protoplasts are not considered "true" plant cells and making them less relevant for biophysical studies. Current protocols for CW recovery in protoplasts vary widely among laboratories and starting materials, requiring lab-specific optimizations that often depend on expert knowledge and qualitative assessments. To address this, we have developed a user-friendly streamlined workflow, the Q-Warg pipeline, which enables quantitative comparison of various conditions for CW recovery post-protoplasting. This pipeline employs fluorescence imaging and tailored processing to measure parameters such as morphometry, cell viability, and CW staining intensity. Using this approach, we optimized culture conditions to obtain single plant cells (SPCs) with recovered CWs. Additionally, we demonstrated the robustness and versatility of the workflow by quantifying different fluorescent signals in protoplast suspensions. Overall, the Q-Warg pipeline provides a widely available and user-friendly solution for robust and unbiased characterization of protoplasts culture. The quantitative data generated by the pipeline may be useful in the future to decipher the mechanisms regulating protoplast viability and regeneration. Significance statementSeveral fields of plant biology, ranging from biotechnology to biomechanics, have recently regained a strong interest in using and studying protoplasts and single cells. Here, we developed a widely accessible quantitative workflow to characterize cell culture recovery after protoplasting along with the demonstration of its usefulness and versatility in various cases. We hope this tool can help other research groups to streamline the procedure needed to establish single plant cell approaches in their lab.

plant biology↗