Sequence-specific protein interaction with a transcriptional enhancer involved in the autoregulated expression of cAMP receptor 1 in Dictyostelium.
Major stages of Dictyostelium development are regulated by secreted, extracellular cAMP through activation of a serpentine receptor family. During early development, oscillations of extracellular cAMP mobilize cells for aggregation; later, continuous exposure to higher extracellular cAMP concentrations downregulates early gene expression and promotes cytodifferentiation and cell-specific gene expression. The cAMP receptor 1 gene CAR1 has two promoters that are differentially responsive to these extracellular cAMP stimuli. The early CAR1 promoter is induced by nM pulses of cAMP, which in turn are generated by CAR1-dependent activation of adenylyl cyclase (AC). Higher, non-fluctuating concentrations of cAMP will adapt this AC stimulus-response, repress the activated early promoter and induce the dormant late promoter. We now identify a critical element of the pulse-induced CAR1 promoter and a nuclear factor with sequence-specific interaction. Mutation of four nucleotides within the element prevents both in vitro protein binding and in vivo expression of an otherwise fully active early CAR1 promoter and multimerization of the wild-type, but not mutant, sequence will confer cAMP regulation to a quiescent heterologous promoter. These cis and trans elements, thus, constitute a part of the molecular response to the cAMP transmembrane signal cascade that regulates early development of Dictyostelium.
Laboratory of Cellular and Developmental Biology, NIDDK (Bldg 6/B1-22) and Howard Hughes Medical Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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D000818:Animals; D001483:Base Sequence; D018983:DNA Footprinting; D004023:Dictyostelium; D004742:Enhancer Elements, Genetic; D019204:GTP-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D006706:Homeostasis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D015800:Protozoan Proteins / Q000096:biosynthesis* / Q000235:genetics; D011953:Receptors, Cyclic AMP / Q000096:biosynthesis* / Q000235:genetics; D017384:Sequence Deletion; D013329:Structure-Activity Relationship; D020079:Terminal Repeat Sequences; D014158:Transcription, Genetic; D015032:Zinc / Q000378:metabolism
D015800:Protozoan Proteins; D011953:Receptors, Cyclic AMP; C068125:cyclic AMP receptor cAR1; D019204:GTP-Binding Proteins; D015032:Zinc