Abstract
Cyclic adenosine monophosphate (cAMP) is a second messenger that relays a wide range of hormone responses. In this paper, we demonstrate that the nuclear pore component RanBP2 acts as a negative regulator of cAMP signaling through Epac1, a cAMP-regulated guanine nucleotide exchange factor for Rap. We show that Epac1 directly interacts with the zinc fingers (ZNFs) of RanBP2, tethering Epac1 to the nuclear pore complex (NPC). RanBP2 inhibits the catalytic activity of Epac1 in vitro by binding to its catalytic CDC25 homology domain. Accordingly, cellular depletion of RanBP2 releases Epac1 from the NPC and enhances cAMP-induced Rap activation and cell adhesion. Epac1 also is released upon phosphorylation of the ZNFs of RanBP2, demonstrating that the interaction can be regulated by posttranslational modification. These results reveal a novel mechanism of Epac1 regulation and elucidate an unexpected link between the NPC and cAMP signaling.
Original language | English |
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Pages (from-to) | 1009-20 |
Number of pages | 12 |
Journal | Journal of Cell Biology |
Volume | 193 |
Issue number | 6 |
DOIs | |
Publication status | Published - 13 Jun 2011 |
Keywords
- Animals
- Cyclic AMP/metabolism
- Guanine Nucleotide Exchange Factors/genetics
- HEK293 Cells
- Humans
- Molecular Chaperones/genetics
- Nuclear Pore/metabolism
- Nuclear Pore Complex Proteins/genetics
- Phosphorylation
- Protein Binding
- Recombinant Fusion Proteins/genetics
- Signal Transduction/physiology
- Two-Hybrid System Techniques
- Zinc Fingers
- ras-GRF1/genetics