title: Intracellular free calcium level and its response to cAMP stimulation in developing Dictyostelium cells transformed with jellyfish apoaequorin cDNA.
abstract: A new method is described for measuring intracellular free calcium concentrations, [(Ca2+)i], in the cells of Dictyostelium discoideum transformed with apoaequorin cDNA of the jellyfish, Aequorea victoria. Aequorin, a calcium-specific indicator, was regenerated in vivo from apoaequorin produced in the cells by incubation with coelenterazine. The results showed that [(Ca2+)i] in developing cells markedly increases at the aggregation stage and again at the culmination stage after a temporary drop at the migration stage. Except for the vegetative stage, the cells at all stages of development exhibit a sharp transient increase in [(Ca2+)i] upon stimulation with a cAMP (50 nM) pulse, high responses being observed at the migration and culmination stages. Separated prestalk cells of migrating slugs contain more than twice as much [(Ca2+)i] and show three times as large a response to cAMP stimulation as prespore cells.
authors.affiliation: National Institute for Basic Biology, Okazaki, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Saran
authors.forename: H
authors.initials: H
authors.lastname: Nakao
authors.forename: M
authors.initials: M
authors.lastname: Tasaka
authors.forename: H
authors.initials: H
authors.lastname: Iida
authors.forename: F I
authors.initials: FI
authors.lastname: Tsuji
authors.forename: V
authors.initials: V
authors.lastname: Nanjundiah
authors.forename: I
authors.initials: I
authors.lastname: Takeuchi
mesh_terms: D000331:Aequorin / Q000235:genetics*; D000818:Animals; D001059:Apoproteins / Q000235:genetics*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002122:Calcium Chloride / Q000494:pharmacology; D002454:Cell Differentiation; D000242:Cyclic AMP / Q000494:pharmacology*; D003600:Cytosol / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics*; D004023:Dictyostelium / Q000187:drug effects / Q000378:metabolism*; D049449:Luminescence; D011994:Recombinant Proteins / Q000235:genetics; D037401:Scyphozoa / Q000235:genetics*; D014162:Transfection
chemical_list: D001059:Apoproteins; D018076:DNA, Complementary; D011994:Recombinant Proteins; C060014:apoaequorin; D000001:Calcimycin; D000331:Aequorin; D000242:Cyclic AMP; D002122:Calcium Chloride; D002118:Calcium