Calreticulin and calnexin in the endoplasmic reticulum are important for phagocytosis
| Autor: | Günther Gerisch, Andrei N. Lupas, Annette Müller-Taubenberger, Evelyn Simmeth, Hewang Li, Mary Ecke |
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| Rok vydání: | 2001 |
| Předmět: |
Phagocytic cup
DNA Complementary Time Factors Calnexin Recombinant Fusion Proteins Phagocytosis Genetic Vectors Green Fluorescent Proteins Endoplasmic Reticulum Article General Biochemistry Genetics and Molecular Biology Animals Genetically Modified Mice Transformation Genetic Calcium-binding protein Cell Adhesion Animals Dictyostelium Molecular Biology Phylogeny Phagosome Mice Inbred BALB C Models Genetic General Immunology and Microbiology biology Chemotaxis General Neuroscience Endoplasmic reticulum Calcium-Binding Proteins biology.organism_classification Protein Structure Tertiary Cell biology Blotting Southern Luminescent Proteins Microscopy Fluorescence Ribonucleoproteins Mutation biology.protein Calcium Calreticulin Protein Binding |
| Zdroj: | The EMBO Journal. 20:6772-6782 |
| ISSN: | 1460-2075 |
| DOI: | 10.1093/emboj/20.23.6772 |
| Popis: | Calreticulin and calnexin are Ca2+-binding proteins with chaperone activity in the endoplasmic reticulum. These proteins have been eliminated by gene replacement in Dictyostelium, the only microorganism known to harbor both proteins; family members in Dictyostelium are located at the base of phylogenetic trees. A dramatic decline in the rate of phagocytosis was observed in double mutants lacking calreticulin and calnexin, whereas only mild changes occurred in single mutants. Dictyostelium cells are professional phagocytes, capable of internalizing particles by a sequence of activities: adhesion of the particle to the cell surface, actin-dependent outgrowth of a phagocytic cup, and separation of the phagosome from the plasma membrane. In the double-null mutants, particles still adhered to the cell surface, but the outgrowth of phagocytic cups was compromised. Green fluorescent protein-tagged calreticulin and calnexin, expressed in wild-type cells, revealed a direct link of the endoplasmic reticulum to the phagocytic cup enclosing a particle, such that the Ca2+ storage capacity of calreticulin and calnexin might directly modulate activities of the actin system during particle uptake. |
| Databáze: | OpenAIRE |
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