A Dictyostelium mutant lacking an F-actin cross-linking protein, the 120-kD gelation factor
| Autor: | Gerhard Isenberg, Eva Wallraff, Marijke Brink, Michael Schleicher, Günther Gerisch, Angelika A. Noegel, Jeffrey E. Segall |
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| Rok vydání: | 1990 |
| Předmět: |
Cell division
Genetic Linkage Mutant macromolecular substances Microfilament Antibodies Dictyostelium discoideum Fungal Proteins Cell membrane Epitopes Cell Movement Cell cortex Cyclic AMP medicine Dictyostelium RNA Messenger Cytoskeleton Actin Repetitive Sequences Nucleic Acid biology Chemotaxis Cell Membrane Microfilament Proteins Articles Cell Biology biology.organism_classification Actins Cell biology medicine.anatomical_structure Mutation Carrier Proteins DNA Probes Cell Division |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| DOI: | 10.1083/jcb.111.4.1477 |
| Popis: | Actin-binding proteins are known to regulate in vitro the assembly of actin into supramolecular structures, but evidence for their activities in living nonmuscle cells is scarce. Amebae of Dictyostelium discoideum are nonmuscle cells in which mutants defective in several actin-binding proteins have been described. Here we characterize a mutant deficient in the 120-kD gelation factor, one of the most abundant F-actin cross-linking proteins of D. discoideum cells. No F-actin cross-linking activity attributable to the 120-kD protein was detected in mutant cell extracts, and antibodies recognizing different epitopes on the polypeptide showed the entire protein was lacking. Under the conditions used, elimination of the gelation factor did not substantially alter growth, shape, motility, or chemotactic orientation of the cells towards a cAMP source. Aggregates of the mutant developed into fruiting bodies consisting of normally differentiated spores and stalk cells. In cytoskeleton preparations a dense network of actin filaments as typical of the cell cortex, and bundles as they extend along the axis of filopods, were recognized. A significant alteration found was an enhanced accumulation of actin in cytoskeletons of the mutant when cells were stimulated with cyclic AMP. Our results indicate that control of cell shape and motility does not require the fine-tuned interactions of all proteins that have been identified as actin-binding proteins by in vitro assays. |
| Databáze: | OpenAIRE |
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