Differentiation-induced alterations in cyclic AMP signaling in the Cath.a differentiated (CAD) neuronal cell line.
Regulation of intracellular cyclic AMP is critical to the modulation of many cellular activities, including cellular differentiation. Moreover, morphological differentiation has been linked to subsequent alterations in the cAMP signaling pathway in various cellular models. The current study was designed to explore the mechanism for the previously reported enhancement of adenylate cyclase activity in Cath.a differentiated cells following differentiation. Differentiation of Cath.a differentiated cells stably expressing the D2L dopamine receptor markedly potentiated both forskolin- and A2-adenosine receptor-stimulated cAMP accumulation. This enhancement was accompanied by a twofold increase in adenylate cyclase 6 (AC6) expression and a dramatic loss in the expression of AC9. The ability of Ca2+ to inhibit drug-stimulated cAMP accumulation was enhanced following differentiation, as was D2L dopamine receptor-mediated inhibition of Galphas-stimulated cAMP accumulation. Differentiation altered basal and drug-stimulated phosphorylation of the cAMP-response element-binding protein, which was independent of changes in protein kinase A expression. The current data suggest that differentiation of the neuronal cell model, Cath.a differentiated cells induces significant alterations in the expression and function of both the proximal and distal portions of the cAMP signaling pathway and may impact cellular operations dependent upon this pathway.
Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, USA.
Christopher A
CA
Johnston
Michael A
MA
Beazely
Matthew L
ML
Bilodeau
Ourania
O
Andrisani
Val J
VJ
Watts
D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D005576:Colforsin / Q000494:pharmacology; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D017362:Cyclic AMP Response Element-Binding Protein / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D043683:Receptors, Adenosine A2 / Q000187:drug effects / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014162:Transfection
D016895:Culture Media, Serum-Free; D017362:Cyclic AMP Response Element-Binding Protein; D007527:Isoenzymes; D043683:Receptors, Adenosine A2; D017448:Receptors, Dopamine D2; C113776:dopamine D2L receptor; D005576:Colforsin; D000242:Cyclic AMP; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D002118:Calcium