Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.1 (adenylate cyclase)
 19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When amoebae of Dictyostelium discoideum develop on gels of polyacrylamide that are derivatized with glucosides, they become capable of aggregation at the same time as cells not exposed to glucosides. However, the aggregation centers and streams of adherent cells formed on immobilized glucosides suddenly disintegrate. The cells repeatedly re-aggregate, but never form tight aggregates as they do on other substrata. Tight aggregates formed in the absence of glucosides disperse after their transfer to glucoside gels, and the cells undergo aggregation-disaggregation cycles. The formation of tight aggregates is correlated with the expression of specific post-aggregative poly(A) RNAs. These RNAs are not expressed in cells developing on glucoside gels, and the dispersal of tight aggregates on such gels is accompanied by the almost complete loss of these RNAs. A developmentally regulated membrane glycoprotein called contact site A, which is a marker of aggregation-competent cells, is normally expressed on glucoside gels. Cyclic AMP is also produced, indicating that the strong increase of adenylate cyclase activity during the preaggregation phase is not affected. In conclusion, cell contact with immobilized glucosides specifically inhibits postaggregative gene expression and arrests development at the aggregation stage.
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PMID:Regulation of gene expression in Dictyostelium discoideum cells exposed to immobilized carbohydrates. 1645 93

When vegetative cells of Dictyostelium discoideum were incubated in nutrient medium containing 5 mM caffeine, adenylate cyclase was induced and exceeded control values 30-fold after 6 h of incubation. The effect was dose-dependent and blocked by cycloheximide. Contact site A, a developmentally regulated membrane glycoprotein characteristic of aggregation-competent cells, was not induced by the treatment. The expression of a developmentally regulated gene coding for an unknown protein and hybridizing with the cDNA clone P26E8 was also stimulated, indicating that the regulation of expression occurs at the transcript level. Cells pretreated with caffeine in growth medium, washed and developed in starvation buffer showed an acceleration of development by 2 h as judged by stream formation and the appearance of contact sites A. The same effects were observed when cells were incubated under heat shock conditions (30 degrees C). The results indicate that caffeine stimulates the expression of devevelopmentally regulated early genes, and that their products, together with exogeneous factor(s), initiate subsequent steps of development.
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PMID:Caffeine and heat shock induce adenylate cyclase in Dictyostelium discoideum. 1645 41


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