Synapsin 1 promotes Aβ generation via BACE1 modulation
Authors:
Masato Maesako aff001; Katarzyna M. Zoltowska aff001; Oksana Berezovska aff001
Authors place of work:
MassGeneral Institute for Neurodegenerative Disease, Alzheimer’s Disease Research Unit, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
aff001
Published in the journal:
PLoS ONE 14(12)
Category:
Research Article
doi:
https://doi.org/10.1371/journal.pone.0226368
Summary
It has been revealed that β-amyloid (Aβ) is generated and released from the presynaptic terminals in activity-dependent manner. However, molecules modulating the presynaptic Aβ generation remain elusive. Here we test the hypothesis that Synapsin 1 (Syn1) may acts as a modulator of the Aβ production. Using biochemical and Förster resonance energy transfer (FRET)-based imaging approaches we have found that Syn1 knock down decreases, whereas (over)expression of Syn1 in cells increases the Aβ levels. Mechanistically, Syn1 does not seem to affect the activity of Presenilin 1 (PS1)/γ-secretase, PS1 conformation, or the proximity between PS1 and amyloid precursor protein (APP). However, we found that Syn1 is involved in up-regulation of the β-site APP cleaving enzyme 1 (BACE1)/β-secretase activity and increases the APP/BACE1 interaction. Therefore, we conclude that Syn1 may promote Aβ production via the modulation of BACE1.
Keywords:
Enzyme-linked immunoassays – Alzheimer's disease – Neurons – proteomics – CHO cells – Co-immunoprecipitation – Fluorescence resonance energy transfer – Synaptic vesicles
Introduction
One of the characteristic pathological features of Alzheimer’s disease (AD) is amyloid plaques deposition in the brain composed of β-amyloid (Aβ). The soluble oligomeric Aβ is believed to be the neurotoxic species disturbing normal synapse function that leads to the memory impairment in AD [1–3]. Aβ derives from the proteolytic processing of the amyloid precursor protein (APP). The β-site APP cleaving enzyme 1 (BACE1), known as β-secretase, cleaves APP at the extramembrane domain, producing the soluble form of APP β (sAPPβ) and membrane-bound APP C-terminus fragment β (APP-CTFβ) [4]. Preseniln 1 (PS1)/γ-secretase subsequently cleaves the APP-CTFβ within the membrane, generating Aβ and APP intracellular domain [5, 6]. Increasing number of evidence suggests that Aβ is released from the presynaptic terminal in a neuronal activity dependent manner [7–10]. Thus, better understanding of the synaptic Aβ regulators would be crucial for potential synapse targeting AD therapeutics.
Several synaptic proteins have been identified as PS1/γ-secretase binding partners and have been shown to affect Aβ production and/or release [11–13]. We have performed mass spectrometry (MS) proteomics screen to identify PS1 binding proteins in mouse brain and have recently shown that a synaptic vesicle-associated protein Synaptotagmin 1 (Syt1), affects PS1/γ-secretase activity and APP processing [13] and regulates Aβ release via direct interaction with PS1 [14]. Synapsin 1 (Syn1) has also appeared in the MS proteomic screen as a novel PS1 interacting protein. Syn1 is known to tether synaptic vesicles to the actin filaments and keep them in the synaptic vesicles reserve pool, thereby modulating neurotransmitter release [15, 16]. However, whether Syn1 may affect the level of Aβ is unknown. In the present study, we used biochemical and Förster resonance energy transfer (FRET)-based imaging techniques to examine the role of Syn1 in the production of Aβ. Here we demonstrate that Syn1 knock down decreases, whereas (over)expression of Syn1 increases the Aβ levels in the conditioned medium. Syn1 modulates neither the activity of PS1/γ-secretase, nor APP and PS1 proximity. Moreover, Syn1 (over)expression does not change PS1 conformation or the Aβ42/40 ratio. On the other hand, we found that Syn1 expression correlates with the strengthened BACE1/β-secretase activity and increases BACE1 proximity interaction with APP. Therefore, we conclude that Syn1 may promote Aβ production via modulation of BACE1.
Material and methods
Ethics statements
The protocol for harvesting of mouse brains and neuronal preparation procedure is in compliance with the NIH guidelines for the use of animals in experiments and was approved by the Massachusetts General Hospital Animal Care and Use Committee (2003N000243 and 2006N000026).
Antibodies and reagents
An anti-FLAG (Wako, Osaka, Japan), anti-sAPPβ (Immuno-Biological Laboratories Co., Ltd, Tokyo, Japan), anti-APP (SIGMA, St. Louis, MO, USA), anti-PS1 loop (Abcam, Cambridge, MA, USA), anti-PS1 NTF (Abcam, Cambridge, MA, USA), anti-BACE1 (EMD Millipore, Burlignton, MA, USA), anti-Syn1 (ECM Biosciences, Versailles, KY, USA) and anti-GAPDH (Cell Signaling Technology, Danvers, CO, USA) antibodies were used in this study. β-Secretase inhibitor was purchased from Millipore-Sigma (Burlignton, MA, USA).
Cell culture, transfection and lentivirus transduction
Primary neuronal cultures were obtained from cerebral cortex and hippocampus of mouse embryos at gestation day 14–16 (Charles River Laboratories, Wilmington, MA, USA). The neurons were dissociated using Papain Dissociation System (Worthington Biochemical Corporation, Lakewood, NJ, USA) and were maintained for 13–15 days in vitro (DIV) in Neurobasal medium containing 2% B27 supplement, 1% GlutaMax, and 1% Pen/Strep mix (Thermo Fisher Scientific, Waltham, MA, USA). 7W or PS70 CHO cells stably overexpressing human APP or both APP and PS1, respectively, were kind gift from Dr. Dennis Selkoe (Brigham and Women’s Hospital/Harvard Medical School, MA, USA) [17]. For transient transfection into these cells, Lipofectamine 3000 (Thermo Fisher Scientific, Waltham, MA, USA) was used according to the manufacturer’s protocol. Plasmid DNA encoding rat Syn1 with the C-terminal FLAG tag was a kind gift from Dr. Hung-Teh Kao (Brown University, RI, USA). The GFP-PS1-RFP (G-PS1-R) FRET-reporter probe, in which EGFP was fused to the N-terminus of PS1 and RFP was inserted into the loop region between transmembrane domains 6 and 7, was used to monitor the conformational change of PS1 [18]. For the knockdown of Syn1 in primary neurons, shRNA of mouse Synapsin1 (VB160629-1009vbn, 3.09 x 108 TU/mL) or that of scramble control (VB150618-10012, 4.71 x 108 TU/mL) was used (VectorBuilder, Santa Clara, CA, USA). The primary neurons were transduced with the lentiviral particles at multiplicity of infection (MOI) 6 at 4–5 days in vitro (DIV). 12 hours post-infection, the medium was replaced and the neurons were cultured for 5 consecutive days before the analysis.
Co-immunoprecipitation (co-IP) and Western blotting
Co-IP was performed as described previously [13]. Briefly, 4–6 months old male C57BL/6 mice were euthanized using CO2. Whole brains or primary neurons were lysed in a buffer containing 1% Triton X100 (Tx100). The protein concentration was normalized by BCA assay (Thermo Fisher Scientific, Waltham, MA, USA). Conjugation of antibody with Protein G Dynabeads (Thermo Fisher Scientific, Waltham, MA, USA) was performed according to the manufacturer’s protocol. The sample and the Dynabeads-antibody complex were incubated overnight and the immnoprecipitated proteins were eluted in the Elution buffer (50 mM Glycine pH2.8, LDS sample buffer, Reducing Agent; Thermo Fisher Scientific, Waltham, MA, USA).
Western blotting was performed as described previously [19]. Briefly, cells were lysed in a buffer containing 1% Tx100 or 1% Tx100 plus 0.25% NP40. After normalizing protein concentrations by BCA assay, the samples were run on Bis-Tris Gels (Thermo Fisher Scientific, Waltham, MA, USA), the proteins were transferred into nitrocellulose membrane (Thermo Fisher Scientific, Waltham, MA, USA) after the electrophoresis, and detected using corresponding primary and HRP-conjugated secondary antibodies. The blots were developed using Western Lightning Plus ECL reagents (PerkinElmer, Boston, MA, USA).
Measurement of extracellular sAPPβ and Aβ
The ELISA kits were used to measure the levels of sAPPβ (Immuno-Biological Laboratories Co., Ltd, Tokyo, Japan), Aβ40 and Aβ42 (Wako, Osaka, Japan). Briefly, after the plasmid transfection into PS70 cells or the lenti-virus transduction into primary neurons (see Results), the cells were washed and incubated with fresh Opti-MEM or Neurobasal medium without serum for 6 hours. Then the culture medium was collected and centrifuged at 600 g for 5 minutes. The supernatant was used for the ELISA measurements. Each value recorded in ELISA was normalized to the total protein concentration of the corresponding cell lysate as determined by the BCA protein assay.
Measurement of BACE1/β-secretase activity
In vitro BACE1 activity was measured by using β-secretase activity kit (Abcam, Cambridge, MA, USA) according to the manufacturer’s protocol. Briefly, the kit uses a β-secretase-specific peptide conjugated to two reporter molecules; EDANS and DABCYL. The fluorescent signal from EDANS is quenched by the physical proximity of the DABCYL. Cleavage of the peptide by β-secretase physically separates the two molecules, allowing for the release of a fluorescent signal. Therefore, the level of enzymatic activity in samples is proportional to the level of fluorescence intensity. 24 hours after transfection of Syn1, the PS70 cells were washed by PBS, collected, and lysed using the Extraction Buffer provided in the kit.
Measurement of PS1/γ-secretase activity
The in vitro PS1/γ-secretase activity assay was performed as described previously [20]. Briefly, the crude homogenates of PS70 cells transiently transfected with Syn1 plasmid or control empty vector were homogenized in 20 mM HEPES (pH 7.4) containing protease inhibitor cocktail (Roche, Indianapolis, IN, USA). The lysates were centrifuged at 3000 x g for 15 minutes. The supernatant was centrifuged further at 100,000 x g for 1 hour in a L8-80 M ultracentrifuge equipped with a Ti70.1 rotor (Beckman Coulter. Inc, CA, USA). The pellet was lysed with 1% CHAPSO in the Solubilized Buffer (50mM HEPES, 150mM NaCl, 5mM MgCl2, 5mM CaCl2, pH7.0), followed by centrifugation at 100,000 x g for 1 hour to obtain cell membrane enriched sample. Alpha-Gal C99-FLAG construct was a kind gift from Dr. Satoru Funamoto (Doshisha University, Kyoto, Japan) and recombinant C99-FLAG was generated in Sf9 cells (Thermo Fisher Scientific, Waltham, MA, USA) as described previously [20]. Equal amounts of 1% CHAPSO-solubilized cell membranes were incubated with the recombinant C99-FLAG for 4 hours at 37°C, and the levels of generated Aβ 40 and Aβ 42 were measured by ELISA (Wako, Osaka, Japan).
Immunocytochemistry (ICC) and Fluorescence Lifetime Imaging Microscopy (FLIM)
ICC and FLIM analysis were performed as described previously [19]. Briefly, after fixation and permeabilization, the cells were immunstained with primary antibodies against APP and PS1 or BACE1. The FLIM assay was used to monitor relative proximity between the fluorescently labeled proteins (e.g. APP and PS1 or BACE) or different domains of the PS1 molecule (PS1 NT and loop). Pulsing Chameleon Ti:Sapphire laser (Coherent Inc., Santa Clara, CA) was used for two-photon fluorophore excitation at 800 nm. The baseline lifetime (t1) of the donor fluorophore was measured in the absence of the acceptor fluorophore (negative control, FRET absent). The donor fluorophore lifetimes were recorded using a high-speed photomultiplier tube (MCP R3809; Hamamatsu, Bridgewater, NJ) and a fast time-correlated single-photon counting acquisition board (SPC-830; Becker &Hickl, Berlin, Germany). In the presence of the acceptor fluorophore, excitation of the donor fluorophore results in reduced donor emission energy if the donor and the acceptor are less than 5–10 nm apart (FRET present). This leads to a characteristic shortening of the donor fluorophore lifetime (t2). The acquired FLIM data were analyzed using SPC Image software (Becker &Hickl). The percent FRET efficiency (%EFRET) was calculated using the following equation: %EFRET = 100*(t1—t2)/t1.
Statistical analysis
The data comparisons were performed using unpaired Student’s t-test. All values are given as means ± SD. p< 0.05 was considered to indicate a significant difference. All experiments in the study were independently repeated at least three times.
Results
Syn1 affects neither PS1/γ-secretase activity nor APP/PS1 proximity
Our recent MS proteomics screen of mouse brain for PS1 binding proteins [13] identified Syn1 as a novel PS1 binding partner. To verify the PS1-Syn1 interaction at endogenous level, we performed the protein co-immunoprecipitation (co-IP) analysis of the mouse brain and primary neuron lysates. Consistent with the MS proteomics, co-IP revealed PS1-Syn1 complex formation in both mouse brain (Fig 1A) and in primary neurons (Fig 1B). To elucidate the potential effect of Syn1 on PS1 function, we first tested the effect of Syn1 expression on the activity of PS1/γ-secretase using an in vitro γ-secretase activity assay [20]. Membrane-enriched fractions prepared from PS70 cells expressing Syn1 or empty-vector control were incubated for 4 hrs with the recombinant C99 Flag, an immediate PS1/γ-secretase substrate, at 37°C, and the levels of released Aβ40 and 42 were measured by ELISA. There was no significant difference in the Aβ levels between Syn1 (+) and Syn1 (-) preparations, indicating that the PS1/γ-secretase activity was not changed by the expression of Syn1 in PS70 cells (Fig 2A). Next, we investigated the effect of Syn1 on APP (the substrate) and PS1/γ-secretase (the enzyme) interaction by monitoring APP/PS1 proximity in intact cells using our previously validated FLIM assay [21]. 7W cells co-transfected with Syn1 and PS1 were immunostained with the Alexa488 labelled APP and Cy3-labeled PS1 antibodies. The anti-PS1 antibody was omitted in the negative FRET/FLIM control samples. As expected, significant shortening of the Alexa488 donor fluorophore lifetime in PS1-APP double-immunostained cells, comparing to the FRET negative control, indicates presence of FRET, i.e., close proximity between the fluorescently labelled APP and PS1 molecules. We found that the FRET efficiency was comparable in Syn1 and empty vector expressing cells, suggesting that Syn1 does not significantly affect the proximity between APP and PS1 (Fig 2B). Finally, it is known that the Aβ42/40 ratio closely correlates with the PS1 conformation [18, 22]; thus, we performed FLIM analysis of the PS1 conformation using the PS1 conformation sensitive GFP-PS1-RFP FRET reporter [18]. We found that Syn1 did not change the GFP-PS1 N-terminus to RFP-loop proximity, as a measure of PS1 conformation (Fig 2C), which was consistent with the unchanged Aβ42/40 ratio (Fig 2D).
Syn1 promotes Aβ production
To determine if Syn1 may affect Aβ production per se, we measured the levels of Aβ40 and Aβ42 in the conditioned medium of primary neurons infected with the lentivirus carrying Syn1 shRNA to suppress the expression of Syn1 (Fig 3A). Despite the lack of Syn1 expression effect on the activity of PS1/γ-secretase or APP and PS1 proximity, we found that the knockdown of Syn1 in primary neurons significantly decreased the levels of both Aβ40 and Aβ42 in the conditioned medium (Fig 3B and 3C) without changing the Aβ42/40 ratio (data not shown). Consistent with this finding, the transient expression of Syn1 in PS70 CHO cells significantly increased the levels of Aβ40 and Aβ42 in the conditioned medium (Fig 4A–4C).
Syn1 enhances BACE1/β-secretase activity
To identify the mechanism by which Syn1 expression leads to increased Aβ level, we investigated the effect of Syn1 expression on BACE1. First, we co-transfected Syn1 or control empty vector with BACE1 into 7W CHO cells stably expressing APP, and immnostained the cells with Alexa488-labelled APP and Cy3-labeled BACE1 antibodies. The proximity between APP and BACE1 was measured by the FLIM analysis in intact cells. Syn1 expression resulted in significantly increased APP/BACE1 proximity (Fig 5A), suggesting that the APP/BACE1 interaction was enhanced by Syn1 expression. We next performed an in vitro BACE1/β-secretase activity assay in PS70 CHO cells and found that Syn1 strengthens the activity of endogenous BACE1 (Fig 5B). Consistent with the results from the FLIM assay and in vitro β-secretase activity assay, the level of sAPPβ was significantly increased in the conditioned medium of Syn1 expressing PS70 cells (Fig 5C). Of note, the effect of Syn1 on BACE1/β-secretase activity and interaction with APP was not due to the altered expression levels of APP and BACE1, as Syn1 did not significantly change the level of APP and BACE1 protein in these cells (Fig 5D). On the other hand, Syn1 knockdown in primary neurons decreased the level of sAPPβ, suggesting that BACE1 activity is tightly associated with the Syn1 expression in neurons (Fig 5E).
Discussion
Local production and accumulation of synaptic Aβ leading to synaptic dysfunction and neurodegeneration has been well documented [3, 7, 23–25]. Though the molecules affecting activity dependent Aβ production in the post-synapse have been reported [12, 25], molecular modulators of the pre-synaptic Aβ are less defined. Here we investigate the role of presynaptic protein: Syn1 on Aβ generation. We show that Syn1 enhances Aβ production by strengthening BACE1/β-secretase activity and promoting the APP-BACE1 interaction.
The level of synaptic Aβ is dynamically influenced by neuronal activity and is believed to be primarily related to the synaptic vesicle exocytosis from the pre-synaptic terminals [7]. Accordingly, the electron microscopy studies have verified presence of the key molecules necessary for the Aβ production—APP [26], BACE1 [27], and, PS1 [13] in the synaptic vesicles. Synaptic vesicles (SV) reside in three different pools: the reserve pool makes up ~80–90% of the total pool, the recycling pool is significantly smaller (~10–15%), and the readily releasable pool consists of a few vesicles (~1%) that seem to be docked to the pre-synaptic membrane and primed for the release [28]. However, exactly where/in what SV pool Aβ is generated and how it is regulated remains unclear. Syn1 is known to tether synaptic vesicles to the actin filaments, thus preventing them from migrating and keeping them in the SV reserve pool [15, 16]. Neuronal activity and consequent Ca2+ influx triggers phosphorylation of the Syn1 [29]. This phosphorylation induces Syn1/actin filaments disintegration [15, 16], leading to release of the synaptic vesicles from the reserve pool. Concurrently, Ca2+ binding to another synaptic vesicle associated protein, Synaptotagmin 1 (Syt1), triggers the migration of synaptic vesicles towards the plasma membrane, with Syt1 mediating the docking, fusion and exocytosis of the readily releasable synaptic vesicles at the synaptic cleft [30–32].
We have uncovered that both Syn1 and Syt1 interact with the PS1/γ-secretase, and recently reported that Syt1 interaction with PS1 is triggered by Ca2+ influx [13, 14]. It has also been shown that APP interacts with a number of pre-synaptic proteins and has been proposed that APP is processed by BACE1 within the synaptic vesicles [33, 34]. Given that the majority of synaptic vesicles reside in the Syn1-tethered reserve pool, and as the present study found that Syn1 modulates BACE1/β-secretase activity and fosters APP-BACE1 interaction, we suggest that APP might be cleaved by BACE1/β-secretase in the reserve pool, thus further refining the presynaptic location of APP cleavage by BACE1. On the other hand, Ca2+ triggered Syt1 interaction with PS1/γ-secretase has been reported to positively modulate γ-secretase activity, Aβ generation and release at the pre-synapse [14]. Taken together, these finding suggest that Syn1 modulates BACE1/β-secretase mediated APP-CTFβ generation in the synaptic vesicles of the reserve pool. Then the APP-CTFβ is further processed by PS1/γ-secretase to produce and release Aβ during the activity-driven exocytosis, and Syt1 may be involved at this stage.
Surprisingly, while PS1/γ-secretase was not significantly affected by Syn1 expression, Syn1 promoted the activity of BACE1/β-secretase. This seeming discrepancy could be explained, at least partially, by recently described physiological interaction between the β- and γ-secretases existing as a distinct β-secretase/γ-secretase enzymatic complex in the brain [35, 36]. It is plausible that Syn1 binding to PS1 may affect BACE1 functioning within the complex. Our study also shows that Syn1 does not seem to affect BACE1 expression but strengthens the BACE1/β-secretase activity. However, the mechanism behind this is unclear. Structural studies established that the active site of BACE1 is covered by a flexible antiparallel β-hairpin, which is believed to regulate substrate access to the active site [37–39]. Furthermore, BACE1 activity is tightly associated with the pH [40] and, importantly, the flexible antiparallel β-hairpin of active BACE1 displays open conformation, which enables the access of substrates into the catalytic site in a pH dependent manner [39]. It is possible that Syn1 may “force” the positioning of BACE1 in its preferable pH environment, thus inducing the BACE1 substrate accessible conformational change. Consistent with this idea, we found that Syn1 (over)expression is linked to decreased proximity between the BACE1 and APP. A previous study has reported that decreased proximity between APP and BACE1 is linked to increased production of Aβ [41]. In the present study, we knocked down Syn1 expression using shRNA to examine the role of Syn1 on Aβ production in primary neurons. Since it has been reported that Syn1 knockdown may impair neuronal functions, such as neurite outgrowth, synaptogenesis, and/or synaptic transmission [42], we could not rule out the possibility that these altered functions could have subsequently affected APP/BACE1 localization and processing, and thus Aβ production.
Conclusions
In summary, the current study reports Syn1 as a novel synaptic regulator of Aβ, and demonstrates that Syn1 promotes Aβ production by strengthening BACE1/β-secretase activity and inducing APP-BACE1 interaction. In addition, our finding further refine the specific presynaptic location/synaptic vesicle pools where APP is processed and Aβ is generated, and point to SV associated proteins, Syn1 and Syt1, as modulators of the pre-synaptic Aβ generation and release.
Supporting information
S1 Fig [pdf]
The original uncropped and unadjusted Western blotting images and all individual data points within column graphs.
Zdroje
1. Lesné S, Koh MT, Kotilinek L, Kayed R, Glabe CG, Yang A, et al. (2006) A specific amyloid-β protein assembly in the brain impairs memory. Nature 440:352–357. doi: 10.1038/nature04533 16541076
2. Shankar GM, Li S, Mehta TH, Garcia-Munoz A, Shepardson NE, Smith I, et al. (2008) Amyloid-β-protein dimers isolated directly from Alzheimer's brains impair synaptic plasticity and memory. Nat Med 14:837–842. doi: 10.1038/nm1782 18568035
3. Koffie R.M., Meyer-Luehmann M., Hashimoto T., Adams K.W., Mielke M.L., Garcia-Alloza M., et al. (2009) Oligomeric amyloid beta associates with postsynaptic densities and correlates with excitatory synapse loss near senile plaques. Proc Natl Acad Sci U S A 106:4012–4017. doi: 10.1073/pnas.0811698106 19228947
4. Vassar R., Bennett B.D., Babu-Khan S., Kahn S., Mendiaz E.A., Denis P., et al. (1999) Beta-secretase cleavage of Alzheimer's amyloid precursor protein by the transmembrane aspartic protease BACE. Science 286:735–741. doi: 10.1126/science.286.5440.735 10531052
5. De Strooper B., Saftig P., Craessaerts K., Vanderstichele H., Guhde G., Annaert W., et al. (1998) Deficiency of presenilin-1 inhibits the normal cleavage of amyloid precursor protein. Nature 391:387–390. doi: 10.1038/34910 9450754
6. Wolfe M.S., Xia W., Ostaszewski B.L., Diehl T.S., Kimberly W.T., and Selkoe D.J. (1999) Two transmembrane aspartates in presenilin-1 required for presenilin endoproteolysis and gamma-secretase activity. Nature 398:513–517. doi: 10.1038/19077 10206644
7. Cirrito J.R., Yamada K.A., Finn M.B., Sloviter R.S., Bales K.R., May P.C., et al. (2005) Synaptic activity regulates interstitial fluid amyloid-beta levels in vivo. Neuron 48:913–922. doi: 10.1016/j.neuron.2005.10.028 16364896
8. Cirrito J.R., Kang J.E., Lee J., Stewart F.R., Verges D.K., Silverio L.M., et al. (2008) Endocytosis is required for synaptic activity-dependent release of amyloid-beta in vivo. Neuron 58:42–51. doi: 10.1016/j.neuron.2008.02.003 18400162
9. Dolev I., Fogel H., Milshtein H., Berdichevsky Y., Lipstein N., Brose N., et al. (2013) Spike bursts increase amyloid-beta 40/42 ratio by inducing a presenilin-1 conformational change. Nat Neurosci 16:587–595. doi: 10.1038/nn.3376 23563578
10. Yamamoto K., Tanei Z., Hashimoto T., Wakabayashi T., Okuno H., Naka Y., et al. (2015) Chronic optogenetic activation augments abeta pathology in a mouse model of Alzheimer disease. Cell Rep 11:859–865. doi: 10.1016/j.celrep.2015.04.017 25937280
11. Uemura K., Lill C.M., Banks M., Asada M., Aoyagi N., Ando K., et al. (2009) N-cadherin-based adhesion enhances Abeta release and decreases Abeta42/40 ratio. J Neurochem 108:350–360. doi: 10.1111/j.1471-4159.2008.05760.x 19046403
12. Wu J., Petralia R.S., Kurushima H., Patel H., Jung M.Y., Volk L., et al. (2011) Arc/Arg3.1 regulates an endosomal pathway essential for activity-dependent beta-amyloid generation. Cell 147:615–628. doi: 10.1016/j.cell.2011.09.036 22036569
13. Kuzuya A., Zoltowska K.M., Post K.L., Arimon M., Li X., Svirsky S., et al. (2016) Identification of the novel activity-driven interaction between synaptotagmin 1 and presenilin 1 links calcium, synapse, and amyloid beta. BMC Biol 14:25. doi: 10.1186/s12915-016-0248-3 27036734
14. Zoltowska K.M., Maesako M., Lushnikova I., Takeda S., Keller L.J., Skibo G., et al. (2017) Dynamic presenilin 1 and synaptotagmin 1 interaction modulates exocytosis and amyloid beta production. Mol Neurodegener 12:15. doi: 10.1186/s13024-017-0159-y 28193235
15. Bahler M., and Greengard P. (1987) Synapsin I bundles F-actin in a phosphorylation-dependent manner. Nature 326:704–707. doi: 10.1038/326704a0 3104800
16. Petrucci T.C., and Morrow J.S. (1987) Synapsin I: an actin-bundling protein under phosphorylation control. J Cell Biol 105:1355–1363. doi: 10.1083/jcb.105.3.1355 3115996
17. Xia W., Zhang J., Kholodenko D., Citron M., Podlisny M.B., Teplow D.B., et al. (1997) Enhanced production and oligomerization of the 42-residue amyloid beta-protein by Chinese hamster ovary cells stably expressing mutant presenilins. J Biol Chem 272:7977–7982. doi: 10.1074/jbc.272.12.7977 9065468
18. Uemura K., Lill C.M., Li X., Peters J.A., Ivanov A., Fan Z., et al. (2009) Allosteric modulation of PS1/gamma-secretase conformation correlates with amyloid beta(42/40) ratio. PLoS One 4:e7893. doi: 10.1371/journal.pone.0007893 19924286
19. Maesako M., Horlacher J., Zoltowska K.M., Kastanenka K.V., Kara E., Svirsky S., et al. (2017) Pathogenic PS1 phosphorylation at Ser367. Elife 6. e19720 doi: 10.7554/eLife.19720 28132667
20. Kakuda N., Funamoto S., Yagishita S., Takami M., Osawa S., Dohmae N., et al. (2006) Equimolar production of amyloid beta-protein and amyloid precursor protein intracellular domain from beta-carboxyl-terminal fragment by gamma-secretase. J Biol Chem 281:14776–14786. doi: 10.1074/jbc.M513453200 16595682
21. Berezovska O, Ramdya P, Skoch J, Wolfe MS, Bacskai BJ, Hyman BT. (2003) Amyloid precursor protein associates with a nicastrin-dependent docking site on the presenilin 1-gamma-secretase complex in cells demonstrated by fluorescence lifetime imaging. J Neurosci 1;23(11):4560–6. doi: 10.1523/JNEUROSCI.23-11-04560.2003 12805296
22. Berezovska O, Lleo A, Herl LD, Frosch MP, Stern EA, Bacskai BJ, et al. (2005) Familial Alzheimer's disease presenilin 1 mutations cause alterations in the conformation of presenilin and interactions with amyloid precursor protein. J Neurosci 16;25(11):3009–17.
23. Takahashi R.H., Milner T.A., Li F., Nam E.E., Edgar M.A., Yamaguchi H., et al. (2002) Intraneuronal Alzheimer abeta42 accumulates in multivesicular bodies and is associated with synaptic pathology. Am J Pathol 161:1869–1879. doi: 10.1016/s0002-9440(10)64463-x 12414533
24. Takahashi R.H., Almeida C.G., Kearney P.F., Yu F., Lin M.T., Milner T.A., et al. (2004) Oligomerization of Alzheimer's beta-amyloid within processes and synapses of cultured neurons and brain. J Neurosci 24:3592–3599. doi: 10.1523/JNEUROSCI.5167-03.2004 15071107
25. Kim S.H., Fraser P.E., Westaway D., St George-Hyslop P.H., Ehrlich M.E., and Gandy S. (2010) Group II metabotropic glutamate receptor stimulation triggers production and release of Alzheimer's amyloid(beta)42 from isolated intact nerve terminals. J Neurosci 30:3870–3875. doi: 10.1523/JNEUROSCI.4717-09.2010 20237257
26. Groemer T.W., Thiel C.S., Holt M., Riedel D., Hua Y., Huve J., et al. (2011) Amyloid precursor protein is trafficked and secreted via synaptic vesicles. PLoS One 6:e18754. doi: 10.1371/journal.pone.0018754 21556148
27. Kandalepas P.C., Sadleir K.R., Eimer W.A., Zhao J., Nicholson D.A., and Vassar R. (2013) The Alzheimer's beta-secretase BACE1 localizes to normal presynaptic terminals and to dystrophic presynaptic terminals surrounding amyloid plaques. Acta Neuropathol 126:329–352. doi: 10.1007/s00401-013-1152-3 23820808
28. Rizzoli S.O., and Betz W.J. (2005) Synaptic vesicle pools. Nat Rev Neurosci 6:57–69. doi: 10.1038/nrn1583 15611727
29. Krueger B.K., Forn J., and Greengard P. (1977) Depolarization-induced phosphorylation of specific proteins, mediated by calcium ion influx, in rat brain synaptosomes. J Biol Chem 252:2764–2773. 323254
30. Brose N, Petrenko AG, Südhof TC, Jahn R. (1992) Synaptotagmin: a calcium sensor on the synaptic vesicle surface. Science 15;256(5059):1021–5. doi: 10.1126/science.1589771 1589771
31. Geppert M., Goda Y., Hammer R.E., Li C., Rosahl T.W., Stevens C.F., et al. (1994) Synaptotagmin I: a major Ca2+ sensor for transmitter release at a central synapse. Cell 79:717–727. doi: 10.1016/0092-8674(94)90556-8 7954835
32. Reist N.E., Buchanan J., Li J., DiAntonio A., Buxton E.M., and Schwarz T.L. (1998) Morphologically docked synaptic vesicles are reduced in synaptotagmin mutants of Drosophila. J Neurosci 18:7662–7673. doi: 10.1523/JNEUROSCI.18-19-07662.1998 9742137
33. Del Prete D., Lombino F., Liu X., and D'Adamio L. (2014) APP is cleaved by Bace1 in pre-synaptic vesicles and establishes a pre-synaptic interactome, via its intracellular domain, with molecular complexes that regulate pre-synaptic vesicles functions. PLoS One 9:e108576. doi: 10.1371/journal.pone.0108576 25247712
34. Gautam V, D'Avanzo C, Berezovska O, Tanzi RE, Kovacs DM. (2015) Synaptotagmins interact with APP and promote Aβ generation. Mol Neurodegener. 23;10:31.
35. Chen A.C., Kim S., Shepardson N., Patel S., Hong S., and Selkoe D.J. (2015) Physical and functional interaction between the alpha- and gamma-secretases: A new model of regulated intramembrane proteolysis. J Cell Biol 211:1157–1176. doi: 10.1083/jcb.201502001 26694839
36. Liu L, Ding L, Rovere M, Wolfe MS, Selkoe DJ. (2019) A cellular complex of BACE1 and γ-secretase sequentially generates Aβ from its full-length precursor. J Cell Biol. Feb 4;218(2):644–663 doi: 10.1083/jcb.201806205 30626721
37. Hong L., Koelsch G., Lin X., Wu S., Terzyan S., Ghosh A.K., et al. (2000) Structure of the protease domain of memapsin 2 (beta-secretase) complexed with inhibitor. Science 290:150–153. doi: 10.1126/science.290.5489.150 11021803
38. Patel S., Vuillard L., Cleasby A., Murray C.W., and Yon J. (2004) Apo and inhibitor complex structures of BACE (beta-secretase). J Mol Biol 343:407–416. doi: 10.1016/j.jmb.2004.08.018 15451669
39. Shimizu H., Tosaki A., Kaneko K., Hisano T., Sakurai T., and Nukina N. (2008) Crystal structure of an active form of BACE1, an enzyme responsible for amyloid beta protein production. Mol Cell Biol 28:3663–3671. doi: 10.1128/MCB.02185-07 18378702
40. Fukumoto H., Cheung B.S., Hyman B.T., and Irizarry M.C. (2002) Beta-secretase protein and activity are increased in the neocortex in Alzheimer disease. Arch Neurol 59:1381–1389. doi: 10.1001/archneur.59.9.1381 12223024
41. Kinoshita A., Fukumoto H., Shah T., Whelan C.M., Irizarry M.C., and Hyman B.T. (2003) Demonstration by FRET of BACE interaction with the amyloid precursor protein at the cell surface and in early endosomes. J Cell Sci 116:3339–3346. doi: 10.1242/jcs.00643 12829747
42. Chin L.S., Li L., Ferreira A., Kosik K.S., Greengard P. (1995) Impairment of axonal development and of synaptogenesis in hippocampal neurons of synpasin1 deficient mice. Proc Natl Acad Sci U S A 92, 9230–34 doi: 10.1073/pnas.92.20.9230 7568107
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PLOS One
2019 Číslo 12
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