Publications by authors named "Katja Thaysen"

Article Synopsis
  • The Niemann-Pick type C (NPC) system in eukaryotes facilitates the integration of sterols into the vacuolar/lysosomal membrane, relying on the integral protein NCR1 and the soluble NPC2 protein for sterol transfer.
  • Research shows that the N-terminal domain (NTD) of NCR1 can bind various lipids including ergosterol, cholesterol, and several fluorescent analogs of lipid species like phosphatidylinositol and sphingosine.
  • The study further demonstrates the versatility of the NCR1/NPC2 system in yeast, highlighting its role in the transport and homeostasis of multiple lipids in addition to ergosterol.
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Polyene macrolides are antifungal substances, which interact with cells in a sterol-dependent manner. While being widely used, their mode of action is poorly understood. Here, we employ ultraviolet-sensitive (UV) microscopy to show that the antifungal polyene natamycin binds to the yeast plasma membrane (PM) and causes permeation of propidium iodide into cells.

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The membrane protein Niemann-Pick type C1 (NPC1, named NCR1 in yeast) is central to sterol homeostasis in eukaryotes. NCR1 is localized to the vacuolar membrane, where it is suggested to carry sterols across the protective glycocalyx and deposit them into the vacuolar membrane. However, documentation of a vacuolar glycocalyx in fungi is lacking, and the mechanism for sterol translocation has remained unclear.

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During starvation in the yeast vacuolar vesicles fuse and lipid droplets (LDs) can become internalized into the vacuole in an autophagic process named lipophagy. There is a lack of tools to quantitatively assess starvation-induced vacuole fusion and lipophagy in intact cells with high resolution and throughput. Here, we combine soft X-ray tomography (SXT) with fluorescence microscopy and use a deep-learning computational approach to visualize and quantify these processes in yeast.

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Niemann-Pick type C (NPC) proteins are essential for sterol homeostasis, believed to drive sterol integration into the lysosomal membrane before redistribution to other cellular membranes. Here, using a combination of crystallography, cryo-electron microscopy, and biochemical and in vivo studies on the Saccharomyces cerevisiae NPC system (NCR1 and NPC2), we present a framework for sterol membrane integration. Sterols are transferred between hydrophobic pockets of vacuolar NPC2 and membrane-protein NCR1.

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