title: Role of the Vps9-domain protein RgfA in Dictyostelium chemotaxis and development.
abstract: Proteins with a Vps9 domain function as guanine nucleotide exchange factors for Rab proteins and can mediate the uptake of cell surface receptors or other molecules through endocytosis. However, genes encoding these proteins have not been previously studied in cells with robust chemotactic capabilities. Several genes encoding Vps9 domains were identified in the genome of Dictyostelium discoideum, and one of the genes, designated as rgfA (DDB_G0272038), was examined for functions in cell growth, development, and chemotaxis. The rgfA gene was expressed during vegetative growth and throughout development, but disruption of this gene resulted in no major alterations in cell growth, macropinocytosis, developmental morphology, or chemotactic movement. However, heterologous expression of RgfA resulted in a delay of developmental morphogenesis and impaired chemotaxis of cells to folate but did not affect macropinocytosis. These results suggest that RgfA might share redundant functions with other Dictyostelium Vps9-domain proteins and that heterologous expression of this protein can alter processes that depend on the reception of external signals.
authors: Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078-3020, USA. jeff.hadwiger@okstate.edu
authors: Jeffrey A
authors: JA
authors: Hadwiger
mesh_terms: D000595:Amino Acid Sequence; D002633:Chemotaxis / Q000235:genetics*; D004023:Dictyostelium / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D004705:Endocytosis / Q000235:genetics; D005492:Folic Acid / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D020662:Guanine Nucleotide Exchange Factors; D011956:Receptors, Cell Surface; D005492:Folic Acid