Epac2 induces synapse remodeling and depression and its disease-associated forms alter spines

Abstract

Dynamic remodeling of spiny synapses is crucial for cortical circuit development, refinement and plasticity, whereas abnormal morphogenesis is associated with neuropsychiatric disorders. We found that activation of Epac2, a PKA-independent cAMP target and Rap guanine-nucleotide exchange factor (GEF), in cultured rat cortical neurons induced spine shrinkage, increased spine motility, removed synaptic GluR2/3-containing AMPA receptors and depressed excitatory transmission, whereas its inhibition promoted spine enlargement and stabilization. Epac2 was required for dopamine D1-like receptor–dependent spine shrinkage and GluR2 removal from spines. Epac2 interaction with neuroligin promoted its membrane recruitment and enhanced its GEF activity. Rare missense mutations in the EPAC2 (also known as RAPGEF4) gene, previously found in individuals with autism, affected basal and neuroligin-stimulated GEF activity, dendritic Rap signaling, synaptic protein distribution and spine morphology. Thus, we identify a previously unknown mechanism that promotes dynamic remodeling and depression of spiny synapses, disruption of which may contribute to some aspects of disease.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Epac2 is present in synapses in cultured cortical pyramidal neurons.
Figure 2: Epac2 activation induces dendritic spine shrinkage, reduces presynaptic contact and enhances spine motility and turnover.
Figure 3: Epac2 interacts with GluR2/3-containing AMPAR and removes them from spines.
Figure 4: Epac2 activation depresses AMPAR-mediated synaptic transmission.
Figure 5: Dopamine D1/D5-like receptors modulate Rap activity, spine morphology and GluR2 surface expression.
Figure 6: Epac2 interacts with neuroligins.
Figure 7: Disease-associated missense mutations affect Epac2 function.
Figure 8: Epac2 missense mutants affect spine morphology.

References

  1. 1

    Holtmaat, A.J. et al. Transient and persistent dendritic spines in the neocortex in vivo. Neuron 45, 279–291 (2005).

    CAS  Article  Google Scholar 

  2. 2

    Kasai, H., Matsuzaki, M., Noguchi, J., Yasumatsu, N. & Nakahara, H. Structure-stability-function relationships of dendritic spines. Trends Neurosci. 26, 360–368 (2003).

    CAS  Article  Google Scholar 

  3. 3

    Nägerl, U.V., Eberhorn, N., Cambridge, S.B. & Bonhoeffer, T. Bidirectional activity-dependent morphological plasticity in hippocampal neurons. Neuron 44, 759–767 (2004).

    Article  Google Scholar 

  4. 4

    Zhou, Q., Homma, K.J. & Poo, M.M. Shrinkage of dendritic spines associated with long-term depression of hippocampal synapses. Neuron 44, 749–757 (2004).

    CAS  Article  Google Scholar 

  5. 5

    Oray, S., Majewska, A. & Sur, M. Dendritic spine dynamics are regulated by monocular deprivation and extracellular matrix degradation. Neuron 44, 1021–1030 (2004).

    CAS  Article  Google Scholar 

  6. 6

    Pickett, J. & London, E. The neuropathology of autism: a review. J. Neuropathol. Exp. Neurol. 64, 925–935 (2005).

    Article  Google Scholar 

  7. 7

    Tada, T. & Sheng, M. Molecular mechanisms of dendritic spine morphogenesis. Curr. Opin. Neurobiol. 16, 95–101 (2006).

    CAS  Article  Google Scholar 

  8. 8

    Jordan, B.A. et al. Identification and verification of novel rodent postsynaptic density proteins. Mol. Cell. Proteomics 3, 857–871 (2004).

    CAS  Article  Google Scholar 

  9. 9

    Peng, J. et al. Semiquantitative proteomic analysis of rat forebrain postsynaptic density fractions by mass spectrometry. J. Biol. Chem. 279, 21003–21011 (2004).

    CAS  Article  Google Scholar 

  10. 10

    Zhu, J.J., Qin, Y., Zhao, M., Van Aelst, L. & Malinow, R. Ras and Rap control AMPA receptor trafficking during synaptic plasticity. Cell 110, 443–455 (2002).

    CAS  Article  Google Scholar 

  11. 11

    Xie, Z., Huganir, R.L. & Penzes, P. Activity-dependent dendritic spine structural plasticity is regulated by small GTPase Rap1 and its target AF-6. Neuron 48, 605–618 (2005).

    CAS  Article  Google Scholar 

  12. 12

    Srivastava, D.P. et al. Rapid enhancement of two-step wiring plasticity by estrogen and NMDA receptor activity. Proc. Natl. Acad. Sci. USA 105, 14650–14655 (2008).

    CAS  Article  Google Scholar 

  13. 13

    Zhu, Y. et al. Rap2-JNK removes synaptic AMPA receptors during depotentiation. Neuron 46, 905–916 (2005).

    CAS  Article  Google Scholar 

  14. 14

    Morozov, A. et al. Rap1 couples cAMP signaling to a distinct pool of p42/44MAPK regulating excitability, synaptic plasticity, learning and memory. Neuron 39, 309–325 (2003).

    CAS  Article  Google Scholar 

  15. 15

    Kawasaki, H. et al. A family of cAMP-binding proteins that directly activate Rap1. Science 282, 2275–2279 (1998).

    CAS  Article  Google Scholar 

  16. 16

    Bos, J.L. Epac proteins: multi-purpose cAMP targets. Trends Biochem. Sci. 31, 680–686 (2006).

    CAS  Article  Google Scholar 

  17. 17

    Bacchelli, E. et al. Screening of nine candidate genes for autism on chromosome 2q reveals rare non-synonymous variants in the cAMP-GEFII gene. Mol. Psychiatry 8, 916–924 (2003).

    CAS  Article  Google Scholar 

  18. 18

    Abrahams, B.S. & Geschwind, D.H. Advances in autism genetics: on the threshold of a new neurobiology. Nat. Rev. Genet. 9, 341–355 (2008).

    CAS  Article  Google Scholar 

  19. 19

    Chih, B., Afridi, S.K., Clark, L. & Scheiffele, P. Disorder-associated mutations lead to functional inactivation of neuroligins. Hum. Mol. Genet. 13, 1471–1477 (2004).

    CAS  Article  Google Scholar 

  20. 20

    Chih, B., Engelman, H. & Scheiffele, P. Control of excitatory and inhibitory synapse formation by neuroligins. Science 307, 1324–1328 (2005).

    CAS  Article  Google Scholar 

  21. 21

    Craig, A.M. & Kang, Y. Neurexin-neuroligin signaling in synapse development. Curr. Opin. Neurobiol. 17, 43–52 (2007).

    CAS  Article  Google Scholar 

  22. 22

    Ulucan, C. et al. Developmental changes in gene expression of Epac and its upregulation in myocardial hypertrophy. Am. J. Physiol. Heart Circ. Physiol. 293, H1662–H1672 (2007).

    CAS  Article  Google Scholar 

  23. 23

    Enserink, J.M. et al. A novel Epac-specific cAMP analogue demonstrates independent regulation of Rap1 and ERK. Nat. Cell Biol. 4, 901–906 (2002).

    CAS  Article  Google Scholar 

  24. 24

    Kang, G. et al. Epac-selective cAMP analog 8-pCPT-2′-O-Me-cAMP as a stimulus for Ca2+-induced Ca2+ release and exocytosis in pancreatic beta-cells. J. Biol. Chem. 278, 8279–8285 (2003).

    CAS  Article  Google Scholar 

  25. 25

    York, R.D. et al. Rap1 mediates sustained MAP kinase activation induced by nerve growth factor. Nature 392, 622–626 (1998).

    CAS  Article  Google Scholar 

  26. 26

    Vossler, M.R. et al. cAMP activates MAP kinase and Elk-1 through a B-Raf– and Rap1-dependent pathway. Cell 89, 73–82 (1997).

    CAS  Article  Google Scholar 

  27. 27

    Jamain, S. et al. Mutations of the X-linked genes encoding neuroligins NLGN3 and NLGN4 are associated with autism. Nat. Genet. 34, 27–29 (2003).

    CAS  Article  Google Scholar 

  28. 28

    Li, Y. et al. The RAP1 guanine nucleotide exchange factor Epac2 couples cyclic AMP and Ras signals at the plasma membrane. J. Biol. Chem. 281, 2506–2514 (2006).

    CAS  Article  Google Scholar 

  29. 29

    Lüthi, A. et al. Hippocampal LTD expression involves a pool of AMPARs regulated by the NSF-GluR2 interaction. Neuron 24, 389–399 (1999).

    Article  Google Scholar 

  30. 30

    Xia, J., Chung, H.J., Wihler, C., Huganir, R.L. & Linden, D.J. Cerebellar long-term depression requires PKC-regulated interactions between GluR2/3 and PDZ domain–containing proteins. Neuron 28, 499–510 (2000).

    CAS  Article  Google Scholar 

  31. 31

    Cheung, U., Atwood, H.L. & Zucker, R.S. Presynaptic effectors contributing to cAMP-induced synaptic potentiation in Drosophila. J. Neurobiol. 66, 273–280 (2006).

    CAS  Article  Google Scholar 

  32. 32

    Zhong, N. & Zucker, R.S. cAMP acts on exchange protein activated by cAMP/cAMP-regulated guanine nucleotide exchange protein to regulate transmitter release at the crayfish neuromuscular junction. J. Neurosci. 25, 208–214 (2005).

    CAS  Article  Google Scholar 

  33. 33

    Gekel, I. & Neher, E. Application of an Epac activator enhances neurotransmitter release at excitatory central synapses. J. Neurosci. 28, 7991–8002 (2008).

    CAS  Article  Google Scholar 

  34. 34

    Ster, J. et al. Epac mediates PACAP-dependent long-term depression in the hippocampus. J. Physiol. (Lond.) 587, 101–113 (2009).

    CAS  Article  Google Scholar 

  35. 35

    Gelinas, J.N. et al. Activation of exchange protein activated by cyclic-AMP enhances long-lasting synaptic potentiation in the hippocampus. Learn. Mem. 15, 403–411 (2008).

    CAS  Article  Google Scholar 

  36. 36

    Ouyang, M., Zhang, L., Zhu, J.J., Schwede, F. & Thomas, S.A. Epac signaling is required for hippocampus-dependent memory retrieval. Proc. Natl. Acad. Sci. USA 105, 11993–11997 (2008).

    CAS  Article  Google Scholar 

  37. 37

    Kelly, M.P. et al. Developmental etiology for neuroanatomical and cognitive deficits in mice overexpressing Galphas, a G-protein subunit genetically linked to schizophrenia. Mol. Psychiatry 14, 398–415 (2009).

    CAS  Article  Google Scholar 

  38. 38

    Frey, U., Huang, Y.Y. & Kandel, E.R. Effects of cAMP simulate a late stage of LTP in hippocampal CA1 neurons. Science 260, 1661–1664 (1993).

    CAS  Article  Google Scholar 

  39. 39

    Otmakhov, N. & Lisman, J.E. Postsynaptic application of a cAMP analogue reverses long-term potentiation in hippocampal CA1 pyramidal neurons. J. Neurophysiol. 87, 3018–3032 (2002).

    CAS  Article  Google Scholar 

  40. 40

    Chen, Z. et al. Roles of dopamine receptors in long-term depression: enhancement via D1 receptors and inhibition via D2 receptors. Receptors Channels 4, 1–8 (1996).

    CAS  Google Scholar 

  41. 41

    Huang, Y.Y., Simpson, E., Kellendonk, C. & Kandel, E.R. Genetic evidence for the bidirectional modulation of synaptic plasticity in the prefrontal cortex by D1 receptors. Proc. Natl. Acad. Sci. USA 101, 3236–3241 (2004).

    CAS  Article  Google Scholar 

  42. 42

    Otani, S., Blond, O., Desce, J.M. & Crepel, F. Dopamine facilitates long-term depression of glutamatergic transmission in rat prefrontal cortex. Neuroscience 85, 669–676 (1998).

    CAS  Article  Google Scholar 

  43. 43

    Gereau, R.W. IV & Conn, P.J. Potentiation of cAMP responses by metabotropic glutamate receptors depresses excitatory synaptic transmission by a kinase-independent mechanism. Neuron 12, 1121–1129 (1994).

    CAS  Article  Google Scholar 

  44. 44

    Smith, W.B., Starck, S.R., Roberts, R.W. & Schuman, E.M. Dopaminergic stimulation of local protein synthesis enhances surface expression of GluR1 and synaptic transmission in hippocampal neurons. Neuron 45, 765–779 (2005).

    CAS  Article  Google Scholar 

  45. 45

    Kayser, M.S., Nolt, M.J. & Dalva, M.B. EphB receptors couple dendritic filopodia motility to synapse formation. Neuron 59, 56–69 (2008).

    CAS  Article  Google Scholar 

  46. 46

    Südhof, T.C. Neuroligins and neurexins link synaptic function to cognitive disease. Nature 455, 903–911 (2008).

    Article  Google Scholar 

  47. 47

    Kojima, S., Vignjevic, D. & Borisy, G.G. Improved silencing vector coexpressing GFP and small hairpin RNA. Biotechniques 36, 74–79 (2004).

    CAS  Article  Google Scholar 

  48. 48

    Dunaevsky, A., Tashiro, A., Majewska, A., Mason, C. & Yuste, R. Developmental regulation of spine motility in the mammalian central nervous system. Proc. Natl. Acad. Sci. USA 96, 13438–13443 (1999).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

We thank R.L. Huganir (Johns Hopkins University) for antibodies to AMPAR and NMDAR subunits, J. Bos (Utrecht University) and P. Stork (Vollum Institute) for plasmids, A. El-Husseini (University of British Columbia) and P. Scheiffele (University of Basel) for antibodies to neuroligin and plasmid constructs, and G. Borisy and S.-I. Kojima (Northwestern University) for the pGSuper plasmid. We thank A.K. Srivastava (J.C. Self Research Institute of Human Genetics) and G. Swanson (Northwestern University) for thoughtful discussion. This work was supported by the National Alliance for Autism Research, the National Alliance for Research on Schizophrenia and Depression, the Alzheimer's Association, grants from the US National Institutes of Health (MH 071316 to P.P., NS057499 to M.P. and CA108647 to L.A.Q.), a pre-doctoral American Heart Association fellowship to K.M.W. and a post-doctoral American Heart Association fellowship to D.P.S.

Author information

Affiliations

Authors

Contributions

K.M.W. and D.P.S. designed and performed the experiments; H.P., M.V.B., M.E.C., Z.X. and K.A.J. carried out experiments; M.Y. and M.P. performed the mEPSC experiments and assisted in data analysis; L.A.Q. contributed reagents and provided technical expertise; and K.M.W., D.P.S. and P.P. wrote the manuscript. P.P. directed the project.

Corresponding author

Correspondence to Peter Penzes.

Supplementary information

Supplementary Text and Figures

Supplementary Figures 1–13, Supplementary Tables 1 and 2, Supplementary Discussion and Supplementary Results (PDF 2005 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Woolfrey, K., Srivastava, D., Photowala, H. et al. Epac2 induces synapse remodeling and depression and its disease-associated forms alter spines. Nat Neurosci 12, 1275–1284 (2009). https://doi.org/10.1038/nn.2386

Download citation

Further reading