Dissection of the cAMP induced cytosolic calcium response in Dictyostelium discoideum: the role of cAMP receptor subtypes and G protein subunits.
The cAMP signaling cascade leading to changes in [Ca2+]i in Dictyostelium discoideum was analyzed using cell lines overexpressing single cAMP receptor subtypes (cAR1-cAR3) or lacking the G(alpha2) or G(beta) subunit of the G protein. Imaging of fura2-dextran-loaded amoebae revealed cAMP-induced [Ca2+]i changes characteristic for each receptor subtype activated. Cells expressing distinct subtypes sort to defined zones during multicellular development suggesting involvement of the specific [Ca2+]i transients in patterning processes. Whereas generation of the [Ca2+]i increase was G(alpha2)-independent, only few cells devoid of G(beta) displayed a [Ca2+]i change after stimulation indicating its participation in the regulation of the calcium homeostasis.
Fakultät für Biologie, Universität Konstanz, Germany.
J
J
Sonnemann
A
A
Aichem
C
C
Schlatterer
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004023:Dictyostelium / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D006706:Homeostasis; D007700:Kinetics; D011953:Receptors, Cyclic AMP / Q000145:classification / Q000378:metabolism*; D013997:Time Factors
D011953:Receptors, Cyclic AMP; D000242:Cyclic AMP; D019204:GTP-Binding Proteins; D002118:Calcium