Endospanin-1 is a negative regulator of the cell surface expression of leptin receptor (OB-R), and endospanin-2 is a homologue of unknown function. We investigated the mechanism for endospanin-1 action in regulating OB-R cell surface expression. Here we show that endospanin-1 and -2 are small integral membrane proteins that localize in endosomes and the trans-Golgi network. Antibody uptake experiments showed that both endospanins are transported to the plasma membrane and then internalized into early endosomes but do not recycle back to the trans-Golgi network. Overexpression of endospanin-1 or endospanin-2 led to a decrease of OB-R cell surface expression, whereas shRNA-mediated depletion of each protein increased OB-R cell surface expression. This increased cell surface expression was not observed with OB-Ra mutants defective in endocytosis or with transferrin and EGF receptors. Endospanin-1 or endospanin-2 depletion did not change the internalization rate of OB-Ra but slowed down its lysosomal degradation. Thus, both endospanins are regulators of postinternalization membrane traffic of the endocytic pathway of OB-R.
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http://dx.doi.org/10.1074/jbc.M111.224857 | DOI Listing |
Elife
December 2024
Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland.
Because of high mutation rates, viruses constantly adapt to new environments. When propagated in cell lines, certain viruses acquire positively charged amino acids on their surface proteins, enabling them to utilize negatively charged heparan sulfate (HS) as an attachment receptor. In this study, we used enterovirus A71 (EV-A71) as model and demonstrated that unlike the parental MP4 variant, the cell-adapted strong HS-binder MP4-97R/167G does not require acidification for uncoating and releases its genome in the neutral or weakly acidic environment of early endosomes.
View Article and Find Full Text PDFMethods Mol Biol
December 2024
Department of Experimental Medicine, Biotechnology, and Molecular Biology Section, Luigi Vanvitelli Campania University, Naples, Italy.
Mesenchymal stromal cells (MSCs) are a heterogeneous population of non-hematopoietic adult stem cells derived from the embryonic mesoderm. They possess self-renewal and multipotent differentiation capabilities, allowing them to give rise to mesodermal cell types, such as osteoblasts, chondroblasts, and adipocytes, as well as non-mesodermal cells, including neuron-like cells and endothelial cells. MSCs play a vital role in maintaining homeostasis across various tissues by facilitating tissue repair, immune regulation, and inflammatory response balance.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
University of Maryland at College Park, Department of Chemical & Biomolecular Engineering, 1223A Chemical and Nuclear Engineering, 20742, College Park, UNITED STATES OF AMERICA.
All-solid-state Li-metal battery (ASSLB) chemistry with thin solid-state electrolyte (SSE) membranes features high energy density and intrinsic safety but suffers from severe dendrite formation and poor interface contact during cycling, which hampers the practical application of rechargeable ASSLB. Here, we propose a universal design of thin Li-metal anode (LMA) via a dynamic stability strategy to address these issues. The ultra-thin LMA (20 μm) is in-situ constructed with uniform highly Li-ion conductive solid-electrolyte interphase and composite-polymer interphase (CPI) via electroplating process.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Fudan University, Department of Chemistry, Room 223, Laboratory of Advanced Materials Building, Songhu Road 2005, Shanghai, Shanghai, CHINA.
Sn redox chemistry in aqueous acidic electrolyte was characterized with high reversibility and kinetics, which is considered as competitive anode material for aqueous batteries. Unfortunately, divalent Sn2+ is unstable in aqueous electrolyte. It was revealed that Sn2+ is easy to be oxidized to tetravalent Sn4+ by dissolved oxygen and then forms precipitate through hydrolysis process, leading to serious performance decay.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Suzhou Medical College of Soochow University, Department of Medicinal Chemistry, 199 Renai Road, Suzhou Industry Park, 215123, Suzhou, CHINA.
Bioorthogonalized light-responsive click-and-uncage platform has enabled precise cell surface engineering and timed payload release, but most of such photoactivatable prodrugs have "always-on" photoactivity leading to the dark toxicity. On the other hand, the conditionally activatable photocage is limited to the application of fluorogenic probe/photosensitizer liberation. Herein, we devise a conditionally activatable theranostic platform based on the tetrazine (Tz)-boron-dipyrromethene (BODIPY) construct, in which tetrazine serves as a quencher motif to disable both the fluorescence and photoresponsivity of BODIPY.
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