Egr-1 modulation of synapsin I expression: permissive effect of forskolin via cAMP
| Autor: | Gerald Thiel, Ann-Marie Conway, Allan James, Brian J. Morris |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Chloramphenicol O-Acetyltransferase
Transcriptional Activation Synapsin I Time Factors Enzyme-Linked Immunosorbent Assay CREB Transfection PC12 Cells Polymerase Chain Reaction Immediate-Early Proteins chemistry.chemical_compound Transactivation Ribonucleases Genes Reporter Cyclic AMP Animals RNA Messenger Early Growth Response Protein 1 Reporter gene Forskolin Expression vector Binding Sites biology Activator (genetics) Reverse Transcriptase Polymerase Chain Reaction Colforsin Cell Biology Synapsins beta-Galactosidase Molecular biology Rats body regions DNA-Binding Proteins nervous system chemistry biology.protein hormones hormone substitutes and hormone antagonists Plasmids Transcription Factors |
| Zdroj: | Cellular signalling. 16(12) |
| ISSN: | 0898-6568 |
| Popis: | A number of candidate Egr-1 neuronal target genes have been identified including the synapsin I gene. Previous studies have shown that over-expression of Egr-1 in cells transfected with an Egr-1 expression vector is sufficient to activate reporter genes linked to regions of the synapsin I promoter, but any effect on the expression of synapsin I within its genomic context has not been demonstrated. We tested our hypothesis that modulation of synapsin I expression by Egr-1 requires the presence of elevated cAMP which would normally be present during periods of neuronal plasticity. Both the adenyl cyclase activator, forskolin (frsk), and the cAMP analogue, Sp-Adenosine 3',5'-cyclic monophosphorothioate triethylammonium salt (Sp-cAMPS), enhanced the ability of Egr-1 to transactivate a CAT reporter plasmid containing multiple copies of the Egr-1 binding site (EBS). Furthermore, Egr-1 alone had minimal effects on synapsin I expression whereas forskolin treatment of PC12 cells profoundly affected the ability of Egr-1 to regulate synapsin I expression. These results suggest that Egr-1 transactivation during neuronal plasticity may rely on a permissive effect of cAMP. |
| Databáze: | OpenAIRE |
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