Transthyretin binds to glucose-regulated proteins and is subjected to endocytosis by the pancreatic β-cell
| Autor: | Martin Köhler, Rebecka Holmberg, Lisa Juntti-Berggren, Per Olof Berggren, Essam Refai, Hans Jörnvall, Nancy Dekki |
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| Rok vydání: | 2011 |
| Předmět: |
endocrine system
media_common.quotation_subject Cell Endocytosis Mice 03 medical and health sciences Cellular and Molecular Neuroscience Insulin-Secreting Cells medicine Animals Prealbumin HSP70 Heat-Shock Proteins Internalization Endoplasmic Reticulum Chaperone BiP Molecular Biology Heat-Shock Proteins Glycoproteins 030304 developmental biology media_common Pharmacology 0303 health sciences Membrane Glycoproteins biology Endoplasmic reticulum 030302 biochemistry & molecular biology Membrane Proteins nutritional and metabolic diseases Clathrin-Coated Vesicles Cell Biology Cell biology Transthyretin medicine.anatomical_structure Cytoplasm Chaperone (protein) biology.protein Molecular Medicine Antibody |
| Zdroj: | Cellular and Molecular Life Sciences |
| ISSN: | 1420-9071 1420-682X |
| Popis: | Transthyretin (TTR) is a functional protein in the pancreatic β-cell. It promotes insulin release and protects against β-cell death. We now demonstrate by ligand blotting, adsorption to specific magnetic beads, and surface plasmon resonance that TTR binds to glucose-regulated proteins (Grps)78, 94, and 170, which are members of the endoplasmic reticulum chaperone family, but Grps78 and 94 have also been found at the plasma membrane. The effect of TTR on changes in cytoplasmic free Ca(2+) concentration ([Ca(2+)](i)) was abolished if the cells were treated with either dynasore, a specific inhibitor of dynamin GTPase that blocks clathrin-mediated endocytosis, or an antibody against Grp78, that prevents TTR from binding to Grp78. The conclusion is that TTR binds to Grp78 at the plasma membrane, is internalized into the β-cell via a clathrin-dependent pathway, and that this internalization is necessary for the effects of TTR on β-cell function. |
| Databáze: | OpenAIRE |
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