Ligand-independent reduction of cAMP receptors in Dictyostelium discoideum cells over-expressing a mutated ras gene.
Drug-resistance selection in Dictyostelium discoideum transformants resulted in up to eight-times-higher ras protein levels. Over-production of the wild-type ras protein did not lead to an aberrant phenotype. Increased levels of the mutated [G12T]ras protein, however, were correlated with severe deficiencies in aggregation and development. This aberrant phenotype is associated with reduced cAMP binding, due to a lower number of cell-surface receptors. We show that both RNA and cAMP-receptor-protein levels are reduced. These results indicate that ras in Dictyostelium discoideum seems to be involved in regulating cAMP-receptor-gene expression.
Ludérus
M E
ME
Cell Biology & Genetics Unit, Leiden University, The Netherlands.
Kesbeke
F
F
Knetsch
M L
ML
Van Driel
R
R
Reymond
C D
CD
Snaar-Jagalska
B E
BE
D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D000242:Cyclic AMP / Q000378:metabolism; D004023:Dictyostelium / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D011905:Genes, ras / Q000235:genetics*; D005839:Gentamicins; D016296:Mutagenesis; D010641:Phenotype; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D011953:Receptors, Cyclic AMP / Q000235:genetics / Q000378:metabolism*; D014170:Transformation, Genetic
D005839:Gentamicins; D012333:RNA, Messenger; D011953:Receptors, Cyclic AMP; C010680:antibiotic G 418; D000242:Cyclic AMP