Page Contents: Abstract | Summary Chart

---

Williams, TD Thomas D, Paschke, PI Peggy I, Kay, RR Robert R, (2019) ' Function of small GTPases in Dictyostelium macropinocytosis. ' Philos. Trans. R. Soc. Lond., B, Biol. Sci. 374 20180150

 

Abstract:Macropinocytosis-the large-scale, non-specific uptake of fluid by cells-is used by Dictyostelium discoideum amoebae 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 in Dictyostelium macropinocytosis. 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'.
Status:	ppublish	Type:	Journal article	Source:	PUBMED	PubMed ID:	30967009

---

 

	Genes addressed in this paper
	gefB	gefF	pikA	pikB	pikC	pikF	pikG	rasB
Topics in this paper
Endocytosis	X	X						X
Genetic Interactions
Strains/Constructs	X	X						X
Cellular Location		X
Mutants/Phenotypes	X	X	X	X	X	X	X	X
Function/Process	X	X						X

	Genes addressed in this paper
	rasC	rasG	rasS
Topics in this paper
Endocytosis	X	X	X
Genetic Interactions	X	X	X
Strains/Constructs	X	X	X
Cellular Location
Mutants/Phenotypes	X	X	X
Function/Process	X	X	X