RRC ID 28986
著者 Rivero F, Köppel B, Peracino B, Bozzaro S, Siegert F, Weijer CJ, Schleicher M, Albrecht R, Noegel AA.
タイトル The role of the cortical cytoskeleton: F-actin crosslinking proteins protect against osmotic stress, ensure cell size, cell shape and motility, and contribute to phagocytosis and development.
ジャーナル J Cell Sci
Abstract We generated Dictyostelium double mutants lacking the two F-actin crosslinking proteins alpha-actinin and gelation factor by inactivating the corresponding genes via homologous recombination. Here we investigated the consequences of these deficiencies both at the single cell level and at the multicellular stage. We found that loss of both proteins severely affected growth of the mutant cells in shaking suspension, and led to a reduction of cell size from 12 microns in wild-type cells to 9 microns in mutant cells. Moreover the cells did not exhibit the typical polarized morphology of aggregating Dictyostelium cells but had a more rounded cell shape, and also exhibited an increased sensitivity towards osmotic shock and a reduced rate of phagocytosis. Development was heavily impaired and never resulted in the formation of fruiting bodies. Expression of developmentally regulated genes and the final developmental stages that were reached varied, however, with the substrata on which the cells were deposited. On phosphate buffered agar plates the cells were able to form tight aggregates and mounds and to express prespore and prestalk cell specific genes. Under these conditions the cells could perform chemotactic signalling and cell behavior was normal at the onset of multicellular development as revealed by time-lapse video microscopy. Double mutant cells were motile but speed was reduced by approximately 30% as compared to wild type. These changes were reversed by expressing the gelation factor in the mutant cells. We conclude that the actin assemblies that are formed and/or stabilized by both F-actin crosslinking proteins have a protective function during osmotic stress and are essential for proper cell shape and motility.
巻・号 109 ( Pt 11)
ページ 2679-91
公開日 1996-11-1
DOI 10.1242/jcs.109.11.2679
PMID 8937986
MeSH Actinin / genetics Actinin / metabolism* Actins / metabolism* Animals Carrier Proteins / genetics Carrier Proteins / metabolism* Cell Movement Cell Size Chemotaxis Cytoskeleton / physiology Dictyostelium / genetics Dictyostelium / growth & development Dictyostelium / metabolism Dictyostelium / physiology* Gene Expression Microfilament Proteins / genetics Microfilament Proteins / metabolism* Mutagenesis Osmolar Concentration Phagocytosis
IF 4.573
引用数 116
WOS 分野 CELL BIOLOGY
リソース情報
細胞性粘菌 S90306