Biology subjects

Böhlig, K.

Publications and source records attributed to Böhlig, K..

3 recordsLinked to original sources

bioRxiv2025

Quantification of lipid sorting during clathrin-mediated endocytosis

Clathrin-mediated endocytosis is a major transport route for proteins from the plasma membrane to the interior of the cell. While the recruitment of cargo proteins to clathrin-coated pits is well understood, it remains an open question if lipids are also sorted by this process. To address this question, we combined super-resolution STED imaging of bifunctional lipid probes with mathematical modeling. Quantification of 10 different lipid species revealed significant differences in pit partitioning, ranging from slight enrichment to moderate exclusion. We find that the lipid asymmetry in the plasma membrane is sufficient to explain the observed trend. Taken together, our findings imply that clathrin-mediated endocytosis has a minor selectivity for cytoplasmic leaflet lipids, but overall does not significantly contribute to lipid sorting compared to non-vesicular trafficking. More broadly, we believe that lipid super-resolution imaging will be a powerful approach to quantify lipid partitioning into membrane structures in cells.

cell biology↗

bioRxiv2025

Visualizing sub-organellar lipid distribution using correlative light and electron microscopy

Lipids and proteins compartmentalize biological membranes into nanoscale domains which are crucial for signaling, intracellular trafficking and many other cellular processes. Studying nanodomain function requires the ability to measure protein and lipid localization at the nanoscale. Current methods for visualizing lipid localization do not meet this requirement. Here, we introduce a correlative light and electron microscopy workflow to image lipids (Lipid-CLEM), combining near-native lipid probes and on-section labeling by click chemistry. This approach enables the quantification of relative lipid densities in membrane nanodomains. We find differential partitioning of sphingomyelin into intraluminal vesicles, recycling tubules, and the boundary membrane of the early endosome, representing a degree of nanoscale organization previously observed only for proteins. We anticipate that our Lipid-CLEM workflow will greatly facilitate the mechanistic analysis of lipid functions in cell biology, allowing for the simultaneous investigation of proteins and lipids during membrane nanodomain assembly and function.

cell biology↗

bioRxiv2024

Bifunctional probes reveal the rules of intracellular ether lipid transport

Ether glycerophospholipids bear a long chain alcohol attached via an alkyl or vinyl ether bond at the sn1 position of the glycerol backbone. Emerging evidence suggests that ether lipids play a significant role in physiology and human health but their precise cellular functions remain largely unknown. Here, we introduce bifunctional ether lipid probes bearing diazirine and alkyne groups to study ether lipid biology. To interrogate the kinetics of intracellular ether lipid transport in mammalian cells we used a combination of fluorescence imaging, machine learning-assisted image analysis and mathematical modelling. We find that alkyl-linked ether lipids are transported up to twofold faster than vinyl-linked plasmalogens, suggesting that the lipid transport machinery can distinguish between linkage types differing by as little as two hydrogen atoms. We find that ether lipid transport predominantly occurs via non-vesicular pathways, with varying contributions from vesicular mechanisms between cell types. Altogether, our results suggest that differential recognition of alkyl- and vinyl ether lipids by lipid transfer proteins contributes to their distinct biological functions. In the future, the probes reported here will enable studying ether lipid biology in much greater detail through identification of interacting proteins and in-depth characterization of intracellular ether lipid dynamics.

cell biology↗