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A Bcl-xL–Drp1 complex regulates synaptic vesicle membrane dynamics during endocytosis

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Abstract

Following exocytosis, the rate of recovery of neurotransmitter release is determined by vesicle retrieval from the plasma membrane and by recruitment of vesicles from reserve pools within the synapse, which is dependent on mitochondrial ATP. The anti-apoptotic Bcl-2 family protein Bcl-xL also regulates neurotransmitter release and recovery in part by increasing ATP availability from mitochondria. We now find, that Bcl-xL directly regulates endocytic vesicle retrieval in hippocampal neurons through protein–protein interaction with components of the clathrin complex. Our evidence suggests that, during synaptic stimulation, Bcl-xL translocates to clathrin-coated pits in a calmodulin-dependent manner and forms a complex with the GTPase Drp1, Mff and clathrin. Depletion of Drp1 produces misformed endocytic vesicles. Mutagenesis studies suggest that formation of the Bcl-xL–Drp1 complex is necessary for the enhanced rate of vesicle endocytosis produced by Bcl-xL, thus providing a mechanism for presynaptic plasticity.

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Figure 1: Bcl-xL overexpression enhances the rate of release of styryl dyes in hippocampal neurons.
Figure 2: Endogenous Bcl-xL participates in normal vesicle pool dynamics.
Figure 3: Bcl-xL increases the rate of mitochondrial ATP-resistant early endocytosis.
Figure 4: Calmodulin-dependent Bcl-xL translocation to synaptic vesicle membranes in stimulated neurons.
Figure 5: Drp1 is co-localized with clathrin and Mff on synaptic vesicles.
Figure 6: Bcl-xL and Drp1 co-localize with synaptophysin on synaptic vesicles.
Figure 7: Drp1 is required for formation of normal endocytic vesicles.
Figure 8: Mutations in the BH2 domain of Bcl-xL disrupt physical and functional interaction with Drp1.

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References

  1. Adams, J. M. & Cory, S. The Bcl-2 apoptotic switch in cancer development and therapy. Oncogene 26, 1324–1337 (2007).

    Article  CAS  Google Scholar 

  2. Banasiak, K. J., Xia, Y. & Haddad, G. G. Mechanisms underlying hypoxia-induced neuronal apoptosis. Prog. Neurobiol. 62, 215–249 (2000).

    Article  CAS  Google Scholar 

  3. Youle, R. J. & Strasser, A. The Bcl-2 protein family: opposing activities that mediate cell death. Nat. Rev. Mol. Cell Biol. 9, 47–59 (2008).

    Article  CAS  Google Scholar 

  4. Fannjiang, Y. et al. BAK alters neuronal excitability and can switch from anti- to pro-death function during postnatal development. Dev. Cell 4, 575–585 (2003).

    Article  CAS  Google Scholar 

  5. Kim, H. et al. Hierarchical regulation of mitochondrion-dependent apoptosis by Bcl-2 subfamilies.. Nat. Cell Biol. 8, 1348–1358 (2006).

    Article  CAS  Google Scholar 

  6. Wang, C. & Youle, R. J. The role of mitochondria in apoptosis*. Annu. Rev. Genet. 43, 95–118 (2009).

    Article  CAS  Google Scholar 

  7. Hardwick, J. M. & Youle, R. J. SnapShot: Bcl-2 proteins. Cell 138, 404 (2009).

    Article  CAS  Google Scholar 

  8. Krajewska, M. et al. Dynamics of expression of apoptosis-regulatory proteins Bid, Bcl-2, Bcl-X, Bax and Bak during development of murine nervous system. Cell Death Differ. 9, 145–157 (2002).

    Article  CAS  Google Scholar 

  9. Li, H. et al. Bcl-xL induces Drp1-dependent synapse formation in cultured hippocampal neurons. Proc. Natl Acad. Sci. USA 105, 2169–2174 (2008).

    Article  CAS  Google Scholar 

  10. Jonas, E. A. et al. Modulation of synaptic transmission by the Bcl-2 family protein BCL-xL. J. Neurosci. 23, 8423–8431 (2003).

    Article  CAS  Google Scholar 

  11. Hickman, J. A., Hardwick, J. M., Kaczmarek, L. K. & Jonas, E. A. Bcl-xL inhibitor ABT-737 reveals a dual role for Bcl-xL in synaptic transmission. J. Neurophysiol. 99, 1515–1522 (2008).

    Article  CAS  Google Scholar 

  12. Alavian, K. N. et al. Bcl-xL regulates metabolic efficiency of neurons through interaction with the mitochondrial F1FO ATP synthase. Nat. Cell Biol. 13, 1224–1233 (2011).

    Article  CAS  Google Scholar 

  13. Verstreken, P. et al. Synaptic mitochondria are critical for mobilization of reserve pool vesicles at Drosophila neuromuscular junctions. Neuron 47, 365–378 (2005).

    Article  CAS  Google Scholar 

  14. Blondeau, F. et al. Tandem MS analysis of brain clathrin-coated vesicles reveals their critical involvement in synaptic vesicle recycling. Proc. Natl Acad. Sci. USA 101, 3833–3838 (2004).

    Article  CAS  Google Scholar 

  15. Dittman, J. & Ryan, T. A. Molecular circuitry of endocytosis at nerve terminals. Annu. Rev. Cell Dev. Biol. 25, 133–160 (2009).

    Article  CAS  Google Scholar 

  16. Slepnev, V. I., Ochoa, G. C., Butler, M. H., Grabs, D. & De Camilli, P. Role of phosphorylation in regulation of the assembly of endocytic coat complexes. Science 281, 821–824 (1998).

    Article  CAS  Google Scholar 

  17. Sakaba, T. & Neher, E. Calmodulin mediates rapid recruitment of fast-releasing synaptic vesicles at a calyx-type synapse. Neuron 32, 1119–1131 (2001).

    Article  CAS  Google Scholar 

  18. Virmani, T., Atasoy, D. & Kavalali, E. T. Synaptic vesicle recycling adapts to chronic changes in activity. J. Neurosci. 26, 2197–2206 (2006).

    Article  CAS  Google Scholar 

  19. Kidokoro, Y. et al. Synaptic vesicle pools and plasticity of synaptic transmission at the Drosophila synapse. Brain Res. Brain Res. Rev. 47, 18–32 (2004).

    Article  CAS  Google Scholar 

  20. Sara, Y., Virmani, T., Deak, F., Liu, X. & Kavalali, E. T. An isolated pool of vesicles recycles at rest and drives spontaneous neurotransmission.. Neuron 45, 563–573 (2005).

    Article  CAS  Google Scholar 

  21. Kuromi, H. & Kidokoro, Y. Two distinct pools of synaptic vesicles in single presynaptic boutons in a temperature-sensitive Drosophila mutant, shibire. Neuron 20, 917–925 (1998).

    Article  CAS  Google Scholar 

  22. Kavalali, E. T. Multiple vesicle recycling pathways in central synapses and their impact on neurotransmission. J. Physiol. 585, 669–679 (2007).

    Article  CAS  Google Scholar 

  23. Sun, T. et al. The role of calcium/calmodulin-activated calcineurin in rapid and slow endocytosis at central synapses. J. Neurosci. 30, 11838–11847 (2010).

    Article  CAS  Google Scholar 

  24. Wu, X. S. et al. Ca(2+) and calmodulin initiate all forms of endocytosis during depolarization at a nerve terminal. Nature Neurosci. 12, 1003–1010 (2009).

    Article  CAS  Google Scholar 

  25. Ryan, T. A. & Smith, S. J. Vesicle pool mobilization during action potential firing at hippocampal synapses. Neuron 14, 983–989 (1995).

    Article  CAS  Google Scholar 

  26. Burrone, J., Li, Z. & Murthy, V. N. Studying vesicle cycling in presynaptic terminals using the genetically encoded probe synaptopHluorin. Nat. Protoc. 1, 2970–2978 (2006).

    Article  CAS  Google Scholar 

  27. Fernandez-Alfonso, T. & Ryan, T. A. The kinetics of synaptic vesicle pool depletion at CNS synaptic terminals. Neuron 41, 943–953 (2004).

    Article  CAS  Google Scholar 

  28. Sankaranarayanan, S., De Angelis, D., Rothman, J. E. & Ryan, T. A. The use of pHluorins for optical measurements of presynaptic activity. Biophys. J. 79, 2199–2208 (2000).

    Article  CAS  Google Scholar 

  29. Miesenbock, G., De Angelis, D. A. & Rothman, J. E. Visualizing secretion and synaptic transmission with pH-sensitive green fluorescent proteins. Nature 394, 192–195 (1998).

    Article  CAS  Google Scholar 

  30. Oltersdorf, T. et al. An inhibitor of Bcl-2 family proteins induces regression of solid tumours. Nature 435, 677–681 (2005).

    Article  CAS  Google Scholar 

  31. Chen, Y. B. et al. Bcl-xL regulates mitochondrial energetics by stabilizing the inner membrane potential. J. Cell Biol. 195, 263–276 (2011).

    Article  CAS  Google Scholar 

  32. Galluzzi, L., Blomgren, K. & Kroemer, G. Mitochondrial membrane permeabilization in neuronal injury. Nat. Rev. Neurosci. 10, 481–494 (2009).

    Article  CAS  Google Scholar 

  33. Kaufmann, T. et al. Characterization of the signal that directs Bcl-x(L), but not Bcl-2, to the mitochondrial outer membrane. J. Cell Biol. 160, 53–64 (2003).

    Article  CAS  Google Scholar 

  34. Kluck, R. M., Bossy-Wetzel, E., Green, D. R. & Newmeyer, D. D. The release of cytochrome c from mitochondria: a primary site for Bcl-2 regulation of apoptosis.. Science 275, 1132–1136 (1997).

    Article  CAS  Google Scholar 

  35. Hsu, Y. T., Wolter, K. G. & Youle, R. J. Cytosol-to-membrane redistribution of Bax and Bcl-X(L) during apoptosis. Proc. Natl Acad. Sci. USA 94, 3668–3672 (1997).

    Article  CAS  Google Scholar 

  36. Berman, S. B. et al. Bcl-xL increases mitochondrial fission, fusion, and biomass in neurons. J. Cell Biol. 184, 707–719 (2009).

    Article  CAS  Google Scholar 

  37. Bossy-Wetzel, E., Barsoum, M. J., Godzik, A., Schwarzenbacher, R. & Lipton, S. A. Mitochondrial fission in apoptosis, neurodegeneration and aging. Curr. Opin. Cell Biol. 15, 706–716 (2003).

    Article  CAS  Google Scholar 

  38. Karbowski, M. et al. Spatial and temporal association of Bax with mitochondrial fission sites, Drp1, and Mfn2 during apoptosis. J. Cell Biol. 159, 931–938 (2002).

    Article  CAS  Google Scholar 

  39. Karbowski, M. & Youle, R. J. Dynamics of mitochondrial morphology in healthy cells and during apoptosis. Cell Death Differ. 10, 870–880 (2003).

    Article  CAS  Google Scholar 

  40. Shaw, J. M. & Nunnari, J. Mitochondrial dynamics and division in budding yeast. Trends Cell Biol. 12, 178–184 (2002).

    Article  CAS  Google Scholar 

  41. Karbowski, M., Neutzner, A. & Youle, R. J. The mitochondrial E3 ubiquitin ligase MARCH5 is required for Drp1 dependent mitochondrial division. J. Cell Biol. 178, 71–84 (2007).

    Article  CAS  Google Scholar 

  42. Uo, T. et al. Drp1 levels constitutively regulate mitochondrial dynamics and cell survival in cortical neurons. Exp.Neurol. 218, 274–285 (2009).

    Article  CAS  Google Scholar 

  43. Otera, H. et al. Mff is an essential factor for mitochondrial recruitment of Drp1 during mitochondrial fission in mammalian cells. J. Cell Biol. 191, 1141–1158 (2010).

    Article  CAS  Google Scholar 

  44. Lenzi, D., Crum, J., Ellisman, M. H. & Roberts, W. M. Depolarization redistributes synaptic membrane and creates a gradient of vesicles on the synaptic body at a ribbon synapse. Neuron 36, 649–659 (2002).

    Article  CAS  Google Scholar 

  45. Lu, Y., Rolland, S. G. & Conradt, B. A molecular switch that governs mitochondrial fusion and fission mediated by the BCL2-like protein CED-9 of Caenorhabditis elegans. Proc. Natl Acad. Sci. USA 108, E813–E822 (2011).

    Article  CAS  Google Scholar 

  46. Li, Z., Okamoto, K., Hayashi, Y. & Sheng, M. The importance of dendritic mitochondria in the morphogenesis and plasticity of spines and synapses. Cell 119, 873–887 (2004).

    Article  CAS  Google Scholar 

  47. Pang, Z. P., Cao, P., Xu, W. & Sudhof, T. C. Calmodulin controls synaptic strength via presynaptic activation of calmodulin kinase II. J. Neurosci. 30, 4132–4142.

  48. Rostovtseva, T. K. et al. Bax activates endophilin B1 oligomerization and lipid membrane vesiculation. J. Biol. Chem. 284, 34390–34399 (2009).

    Article  CAS  Google Scholar 

  49. Jonas, E. A. et al. Proapoptotic N-truncated BCL-xL protein activates endogenous mitochondrial channels in living synaptic terminals. Proc. Natl Acad. Sci. USA 101, 13590–13595 (2004).

    Article  CAS  Google Scholar 

  50. Basanez, G. et al. Bax-type apoptotic proteins porate pure lipid bilayers through a mechanism sensitive to intrinsic monolayer curvature. J. Biol. Chem. 277, 49360–49365 (2002).

    Article  CAS  Google Scholar 

  51. Basanez, G. et al. Pro-apoptotic cleavage products of Bcl-xL form cytochrome c-conducting pores in pure lipid membranes. J. Biol. Chem. 276, 31083–31091 (2001).

    Article  CAS  Google Scholar 

  52. Karbowski, M., Jeong, S. Y. & Youle, R. J. Endophilin B1 is required for the maintenance of mitochondrial morphology. J. Cell Biol. 166, 1027–1039 (2004).

    Article  CAS  Google Scholar 

  53. Farsad, K. et al. Generation of high curvature membranes mediated by direct endophilin bilayer interactions. J. Cell Biol. 155, 193–200 (2001).

    Article  CAS  Google Scholar 

  54. Ringstad, N. et al. Endophilin/SH3p4 is required for the transition from early to late stages in clathrin-mediated synaptic vesicle endocytosis. Neuron 24, 143–154 (1999).

    Article  CAS  Google Scholar 

  55. Schuske, K. R. et al. Endophilin is required for synaptic vesicle endocytosis by localizing synaptojanin. Neuron 40, 749–762 (2003).

    Article  CAS  Google Scholar 

  56. Milosevic, I. et al. Recruitment of endophilin to clathrin-coated pit necks is required for efficient vesicle uncoating after fission. Neuron 72, 587–601 (2011).

    Article  CAS  Google Scholar 

  57. Morgan, J. R., Augustine, G. J. & Lafer, E. M. Synaptic vesicle endocytosis: the races, places, and molecular faces. Neuromol. Med. 2, 101–114 (2002).

    Article  CAS  Google Scholar 

  58. Krueger, S. R., Kolar, A. & Fitzsimonds, R. M. The presynaptic release apparatus is functional in the absence of dendritic contact and highly mobile within isolated axons. Neuron 40, 945–957 (2003).

    Article  CAS  Google Scholar 

  59. Brewer, G. J. Isolation and culture of adult rat hippocampal neurons. J. Neurosci. Methods 71, 143–155 (1997).

    Article  CAS  Google Scholar 

  60. Lois, C., Hong, E. J., Pease, S., Brown, E. J. & Baltimore, D. Germline transmission and tissue-specific expression of transgenes delivered by lentiviral vectors. Science 295, 868–872 (2002).

    Article  CAS  Google Scholar 

  61. Allen, T. G. Preparation and maintenance of single-cell micro-island cultures of basal forebrain neurons. Nat. Protoc. 1, 2543–2550 (2006).

    Article  CAS  Google Scholar 

  62. Komai, S. et al. Postsynaptic excitability is necessary for strengthening of cortical sensory responses during experience-dependent development. Nat. Neurosci. 9, 1125–1133 (2006).

    Article  CAS  Google Scholar 

  63. Tokuyasu, K. T. A technique for ultracryotomy of cell suspensions and tissues. J. Cell Biol. 57, 551–565 (1973).

    Article  CAS  Google Scholar 

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Acknowledgements

The authors wish to acknowledge L. Kaczmarek for thoughtful discussions of the data. The authors also thank G. Meisenbock (Center for Neural Circuits and Behaviour University of Oxford, UK) for providing synaptopHluorin for the sPH studies.

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Authors and Affiliations

Authors

Contributions

H.L. performed experiments, analyses and intellectual contributions; K.N.A. prepared novel reagents, performed experiments, analyses, intellectual contributions and prepared figures; E.L. assisted K.N.A. in preparing reagents and performing experiments; N.M. performed experiments and analyses; A.J. performed experiments and analyses; P.Z. performed experiments and analyses; P.L. prepared novel reagents for experiments; M.G. performed EM experiments; T.U. prepared novel reagents and performed experiments and analyses; J.G. performed experiments; C.R. supervised EM experiments; R.S.D. supervised work performed by P.L.; R.S.M. provided intellectual contribution and supervised experiments performed by T.U.; E.A.J. performed analyses, wrote the manuscript and provided intellectual contributions for, supervision of, and conception and planning of the project.

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Correspondence to Elizabeth A. Jonas.

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The authors declare no competing financial interests.

Integrated supplementary information

Supplementary Figure 1 Further fluorescence analysis for FM 5-95 experiments.

A. Maximum fluorescence values minus the minimum fluorescence values for all experiments in Figs 1 and 2 (***P<0.0001; **P = 0.0077; *P = 0.04). B. Normalized fluorescence change in 90 mM KCl ×3 (5 min rest in normal Tyrode’s wash medium in between each stimulus); N = 9 GFP ctl puncta, 9 GFP-Bcl-xL puncta, 3 independent coverslips were used for each group. Bleaching curve shows normalized fluorescence change in the absence of stimulation. Statistics are represented as mean+/-S.E.M.

Supplementary Figure 2 Transfection of shRNA constructs decreases Bcl-xL, Drp1 and calmodulin protein levels. Purity of subcellular fractions of hippocampal lysate.

A. Immunoblots of lysate of SHSY5Y cells expressing Bcl-xL shRNA or Bcl-xL shRNA in combination with Bcl-xL shRNA resistant constructs. B. (left panel) Immunoblots of lysate of hippocampal neurons expressing scrambled shRNA or Bcl-xL shRNA. (right panel) Immunoblots of lysate of hippocampal neurons overexpressing or not GFP-Bcl-xL. C. Immunoblots with indicated antibodies performed on lysate of hippocampal neurons expressing calmodulin shRNA or scrambled shRNA. D. (Left panel) Immunoblots of subcellular fractions using the indicated antibodies of non-stimulated cultured hippocampal neuron lysate. (Right panel) Immunoblots of subcellular fractions using the indicated antibodies of cultured hippocampal neuron lysate from neurons stimulated with 90 mM KCl for 90 s. E. Immunoblots of subcellular fractions (as indicated) of cultured hippocampal neuron lysate using the indicated antibodies. Left lane shows cell lysate. F. Fluorescent, phase and overlay images of cultured hippocampal neurons transduced with lentivirus construct for GFP-Drp1 shRNA. 100% of cells are transduced. Scale bar, 100 μm. G. Immunoblots of Drp1 shRNA knockdown and overexpression of Drp1 shRNA resistant constructs in 293T cells. H. Immunoblots of lysate of cortical neurons expressing Drp1 shRNA at indicated concentrations. I. Immunogold labeling of Drp1 in scrambled control and Drp1 shRNA-expressing cultured hippocampal neurons (N = 13micrographs for scrambled control, N = 21micrographs for Drp1 shRNA; ***p<0.0001). The average number of synapses in each micrograph was not different between the two groups (1.42 ± 0.14 for Drp shRNA, 1.3 ± 0.13 for scrambled control). Statistics are represented as mean+/-S.E.M.

Supplementary Figure 3 Drp1 localizes to mitochondria and anti-Drp1 and anti-Dynamin I/II antibodies are specific.

A. Immuno-electron micrograph shows localization of Drp1-labeled particles to mitochondria. B. Immunoblots for Drp1 of indicated sub-fractions of cell lysates of cultured unstimulated hippocampal neurons or cultured hippocampal neurons stimulated with 90 mM KCl for 90 s with or without CaMi. GAPDH serves as protein control for cytosolic protein amount, COX IV as control for mitochondrial protein amount, synaptotagmin as control for synaptic vesicle membrane protein amount. C. Immunoblot of rat brain lysate probed with the indicated antibodies.

Supplementary Figure 4 Non-normalized fluorescent data for synaptopHluorin experiments before and after bafilomycin.

A. SynaptopHluorin experiments comparing effects of bafilomycin on GFP-Bcl-xL over-expressing and GFP expressing neurons. B. SynaptopHluorin experiments comparing effects of bafilomycin on Bcl-xL shRNA-expressing cells and on neurons expressing scrambled control shRNA.

Supplementary Figure 5 Uncropped images of films for the key experiments in the main figures.

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Li, H., Alavian, K., Lazrove, E. et al. A Bcl-xL–Drp1 complex regulates synaptic vesicle membrane dynamics during endocytosis. Nat Cell Biol 15, 773–785 (2013). https://doi.org/10.1038/ncb2791

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