Function of small GTPases in Dictyostelium macropinocytosis
| Autor: | Robert R. Kay, Thomas D. Williams, Peggy Paschke |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0303 health sciences
biology Pinocytosis Mutant Small G Protein GTPase biology.organism_classification Endocytosis Dictyostelium General Biochemistry Genetics and Molecular Biology Dictyostelium discoideum Cell biology 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine chemistry Phosphatidylinositol General Agricultural and Biological Sciences 030217 neurology & neurosurgery 030304 developmental biology Monomeric GTP-Binding Proteins |
| Zdroj: | Philosophical transactions of the Royal Society of London. Series B, Biological sciences. 374(1765) |
| ISSN: | 1471-2970 |
| Popis: | Macropinocytosis—the large-scale, non-specific uptake of fluid by cells—is used byDictyostelium discoideumamoebae to obtain nutrients. These cells form circular ruffles around regions of membrane defined by a patch of phosphatidylinositol (3,4,5)-trisphosphate (PIP3) and the activated forms of the small G-proteins Ras and Rac. When this ruffle closes, a vesicle of the medium is delivered to the cell interior for further processing. It is accepted that PIP3 is required for efficient macropinocytosis. Here, we assess the roles of Ras and Rac inDictyosteliummacropinocytosis. Gain-of-function experiments show that macropinocytosis is stimulated by persistent Ras activation and genetic analysis suggests that RasG and RasS are the key Ras proteins involved. Among the activating guanine exchange factors (GEFs), GefF is implicated in macropinocytosis by an insertional mutant. The individual roles of Rho family proteins are little understood but activation of at least some may be independent of PIP3.This article is part of the Theo Murphy meeting issue ‘Macropinocytosis’. |
| Databáze: | OpenAIRE |
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