Differential distribution of cAMP receptors cAR2 and cAR3 during Dictyostelium development.
Signal transduction via a family of cAMP receptor subtypes (cARs) is critical for proper development in the cellular slime mold Dictyostelium. Genes encoding four related subtypes have been cloned and their expression, based on RNA accumulation, has been previously reported. Here we report the differential spatial and temporal distribution of cAR2 and cAR3 proteins, based on indirect double immunofluorescence. Cells were transformed with a carB::lacZ construct, and an antibody against beta-galactosidase was used to visualize cAR2 expression. Simultaneously, a cAR3-specific antibody was used to identify cAR3-expressing cells. Results indicate that by the time of tip formation (12-14 hr) both receptors are expressed and distribute in a virtually nonoverlapping pattern, with cAR2 being expressed on anterior, prestalk cells and cAR3 present in the rest of the organism. Differential distribution of these two receptor subtypes may result in distinct cAMP signaling mechanisms in the two major regions of the organism.
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Department of Anatomy and Cell Biology, Emory University School of Medicine, Atlanta, Georgia 30322-3030, USA.
Saxe
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D000818:Animals; D004023:Dictyostelium / Q000254:growth & development*; D019084:Fluorescent Antibody Technique, Indirect; D018507:Gene Expression Regulation, Developmental; D011953:Receptors, Cyclic AMP / Q000276:immunology / Q000302:isolation & purification*; D013997:Time Factors; D014018:Tissue Distribution; D014170:Transformation, Genetic
C079746:CAR2 protein, Dictyostelium discoideum; C079747:CAR3 protein, Dictyostelium discoideum; D011953:Receptors, Cyclic AMP