1. The Steroid Hormone 20-Hydroxyecdysone Enhances Gene Transcription through the cAMP Response Element-binding Protein (CREB) Signaling Pathway.
- Author
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Jing YP, Wang D, Han XL, Dong DJ, Wang JX, and Zhao XF
- Subjects
- Animals, Blotting, Western, Cell Line, Cyclic AMP Response Element-Binding Protein metabolism, Cyclic AMP-Dependent Protein Kinases genetics, Cyclic AMP-Dependent Protein Kinases metabolism, Gene Expression Regulation, Developmental drug effects, Insect Proteins metabolism, Larva genetics, Larva growth & development, Larva metabolism, Metamorphosis, Biological genetics, Moths genetics, Moths growth & development, Moths metabolism, Phosphorylation drug effects, Protein Binding, Protein Kinase C genetics, Protein Kinase C metabolism, RNA Interference, Reverse Transcriptase Polymerase Chain Reaction, Cyclic AMP Response Element-Binding Protein genetics, Ecdysterone pharmacology, Insect Proteins genetics, Signal Transduction genetics, Transcription, Genetic drug effects
- Abstract
Animal steroid hormones regulate gene transcription through genomic pathways by binding to nuclear receptors. These steroid hormones also rapidly increase intracellular calcium and cyclic adenosine monophosphate (cAMP) levels and activate the protein kinase C (PKC) and protein kinase A (PKA) nongenomic pathways. However, the function and mechanism of the nongenomic pathways of the steroid hormones are unclear, and the relationship between the PKC and PKA pathways is also unclear. We propose that the steroid hormone 20-hydroxyecdysone (20E) activates the PKA pathway to enhance 20E-induced gene transcription in the lepidopteran insect Helicoverpa armigera The expression of the catalytic subunit 1 of PKA (PKAC1) increased during metamorphosis, and PKAC1 knockdown blocked pupation and repressed 20E-responsive gene expression. 20E regulated PKAC1 phosphorylation at threonine 200 and nuclear translocation through an ecdysone-responsive G-protein-coupled receptor 2. PKAC1 induced cAMP response element-binding protein (CREB) phosphorylation at serine 143, which bound to the cAMP response element on DNA to enhance 20E-responsive gene transcription. Through ecdysone-responsive G-protein-coupled receptor 2, 20E increased cAMP levels, which induced CREB PKA phosphorylation and 20E-responsive gene expression. This study demonstrates that the PKA/CREB pathway tightly and critically regulates 20E-induced gene transcription as well as its relationship with the 20E-induced PKC pathway., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2016
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