Clathrin-mediated endocytosis (CME) is critical for cellular signal transduction, receptor recycling, and membrane homeostasis in mammalian cells. Acute depletion of cholesterol disrupts CME, motivating analysis of CME dynamics in the context of human disorders of cholesterol metabolism. We report that inhibition of post-squalene cholesterol biosynthesis impairs CME. Imaging of membrane bending dynamics and the CME pit ultrastructure reveals prolonged clathrin pit lifetimes and shallow clathrin-coated structures, suggesting progressive impairment of curvature generation correlates with diminishing sterol abundance. Sterol structural requirements for efficient CME include 3' polar head group and B-ring conformation, resembling the sterol structural prerequisites for tight lipid packing and polarity. Furthermore, Smith-Lemli-Opitz fibroblasts with low cholesterol abundance exhibit deficits in CME-mediated transferrin internalization. We conclude that sterols lower the energetic costs of membrane bending during pit formation and vesicular scission during CME and suggest that reduced CME activity may contribute to cellular phenotypes observed within disorders of cholesterol metabolism.
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http://dx.doi.org/10.1016/j.celrep.2021.110008 | DOI Listing |
Materials (Basel)
December 2024
Department of Advanced Materials Engineering, Keimyung University, Daegu 42601, Republic of Korea.
We demonstrated a versatile and robust strategy to create spatially defined periodic wrinkles in gradient striped polymer films through the coupled process of controlled evaporative self-assembly (CESA) and mechanically driven surface wrinkling. The mechanical properties of patterned-gradient polymer thin films were investigated by wrinkling methodology in a fast and simple manner. Understanding of the complex wrinkles can provide insights into the growth mechanism of most biological species that can be explained by competition between bending and stretching energies, e.
View Article and Find Full Text PDFFront Neurol
December 2024
Department of Otorhinolaryngology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Objectives: Multiple studies have described the onset and variable incidence of postoperative acute vertigo following cochlear implant (CI) surgery. However, postoperative imaging has not yet been specifically evaluated with special focus on vertigo. The aim of this study is to assess the incidence and causes of new-onset, acute postoperative vertigo following CI surgery using cone beam computed tomography (CBCT).
View Article and Find Full Text PDFUnlabelled: Cytoplasmic proteins must recruit to membranes to function in processes such as endocytosis and cell division. Many of these proteins recognize not only the chemical structure of the membrane lipids, but the curvature of the surface, binding more strongly to more highly curved surfaces, or 'curvature sensing'. Curvature sensing by amphipathic helices is known to vary with membrane bending rigidity, but changes to lipid composition can simultaneously alter membrane thickness, spontaneous curvature, and leaflet symmetry, thus far preventing a systematic characterization of lipid composition on such curvature sensing through either experiment or simulation.
View Article and Find Full Text PDFNano Lett
January 2025
School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
Sci Rep
January 2025
Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
α-Klotho (KLA) is a type-1 membranous protein that can associate with fibroblast growth factor receptor (FGFR) to form co-receptor for FGF23. The ectodomain of unassociated KLA is shed as soluble KLA (sKLA) to exert FGFR/FGF23-independent pleiotropic functions. The previously determined X-ray crystal structure of the extracellular region of sKLA in complex with FGF23 and FGFR1c suggests that sKLA functions solely as an on-demand coreceptor for FGF23.
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