Identification of two highly homologous presynaptic proteins distinctly localized at the dendritic and somatic synapses

Takahashi, Seiichi; Yamamoto, Hiroshi; Matsuda, Zene; Ogawa, Michael Y.; Yagyu, Ken-ichi; Taniguchi, Tadatsugu; Miyata, Takaki; Kaba, Hideto; Higuchi, Takuma; Okutani, Fumino

doi:10.1016/0014-5793(95)00713-j

Cited by 101 publications

(19 citation statements)

References 24 publications

(19 reference statements)

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“…The AH motif was initially identified by inspection of the CPX-1 sequence (Wragg et al, 2013), though a similar sequence was noted in mammalian complexins by others (Takahashi et al, 1995; Seiler et al, 2009). We confirmed membrane-association of the AH motif using NMR binding assays, and demonstrated that the AH motif becomes helical upon binding to highly curved liposomes using a combination of CD spectroscopy and mutational analysis (Seiler et al, 2009; Wragg et al, 2013; Snead et al, 2014).…”

Section: Discussionmentioning

confidence: 84%

Unique Structural Features of Membrane-Bound C-Terminal Domain Motifs Modulate Complexin Inhibitory Function

Snead

Lai

Wragg

et al. 2017

Front. Mol. Neurosci.

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Complexin is a small soluble presynaptic protein that interacts with neuronal SNARE proteins in order to regulate synaptic vesicle exocytosis. While the SNARE-binding central helix of complexin is required for both the inhibition of spontaneous fusion and the facilitation of synchronous fusion, the disordered C-terminal domain (CTD) of complexin is specifically required for its inhibitory function. The CTD of worm complexin binds to membranes via two distinct motifs, one of which undergoes a membrane curvature dependent structural transition that is required for efficient inhibition of neurotransmitter release, but the conformations of the membrane-bound motifs remain poorly characterized. Visualizing these conformations is required to clarify the mechanisms by which complexin membrane interactions regulate its function. Here, we employ optical and magnetic resonance spectroscopy to precisely define the boundaries of the two CTD membrane-binding motifs and to characterize their conformations. We show that the curvature dependent amphipathic helical motif features an irregular element of helical structure, likely a pi-bulge, and that this feature is important for complexin inhibitory function in vivo.

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Section: Discussionmentioning

confidence: 84%

Unique Structural Features of Membrane-Bound C-Terminal Domain Motifs Modulate Complexin Inhibitory Function

Snead

Lai

Wragg

et al. 2017

Front. Mol. Neurosci.

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“…These protein complexes were confirmed by both 2-D BN/SDS-PAGE and co-IP assays. While SNARE-Cplx1 oligomers were expected (63; 64), SNAP25-VAMP dimers were a surprise. In SNARE assembly, t-SNAREs (Stx1-SNAP25) are formed first, and v-SNAREs (VAMP) are attached later (61).…”

Section: Discussionmentioning

confidence: 98%

“…Cplx1 is mainly expressed in inhibitory neurons, while excitatory terminals are enriched in Cplx2 (63; 64). Orbitofrontal GABAergic, but not glutamatergic neurons may display aberrant SNARE complex activity, which could result in constitutive inhibition of the glutamate system, and perhaps contribute to lower OFC function (8).…”

Section: Discussionmentioning

confidence: 99%

Increased SNARE Protein-Protein Interactions in Orbitofrontal and Anterior Cingulate Cortices in Schizophrenia

Ramos-Miguel

Beasley

Dwork

et al. 2015

Biological Psychiatry

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Background Synaptic dysfunction in schizophrenia may be associated with abnormal expression or function of SNARE proteins (syntaxin, SNAP25, VAMP), forming the molecular complex underlying neurosecretion. The impact of such abnormalities on efficient SNARE heterotrimer formation is poorly understood. We investigated putative SNARE dysfunction, along with possible roles for the SNARE binding partners Munc18-1, complexins (Cplx) 1/2 and synaptotagmin, in brains from autopsies of individuals with and without schizophrenia. Methods Postmortem samples were obtained from orbitofrontal (OFC) and/or anterior cingulate (ACC) cortices from two separate cohorts (n = 15+15 schizophrenia cases, n = 13+15 controls). SNARE interactions were studied by immunoprecipitation and one- or two-dimensional blue native electrophoresis (BN-PAGE). Results In the first cohort, syntaxin, Munc18-1 and Cplx1, but not VAMP, Cplx2 or synaptotagmin, were two-fold enriched in SNAP25-immunoprecipitated products from schizophrenia OFC in the absence of any alterations in total tissue homogenate levels of these proteins. In BN-PAGE, the SNARE heterotrimer was identified as a 150-kDa complex, increased in schizophrenia samples from Cohort 1 (OFC: +45%; ACC: +44%) and Cohort 2 (OFC: +40%), with lower 70-kDa SNAP25-VAMP dimer (−37%) in the OFC. Upregulated 200-kDa SNARE-Cplx1 (+65%), and downregulated 550-kDa Cplx1-containing oligomers (−24%) in schizophrenia OFC were identified by BN-PAGE. These findings were not explained by postmortem interval, antipsychotic medication, or other potentially confounding variables. Conclusions The findings support the hypothesis of upregulated SNARE complex formation in schizophrenia OFC, possibly favored by enhanced affinity for Munc18-1 and/or Cplx1. These alterations offer new therapeutic targets for schizophrenia.

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“…For example, adult mammalian retinal ribbon synapses selectively express the complexin 3/4 subfamily [22,23]. The mammalian complexins are a family of small, hydrophilic proteins encoded by four genes that can be grouped into two subfamilies based upon sequence identity and expression patterns [23-26]. Complexins 1 and 2 share approximately 80% amino acid identity and are enriched at conventional synapses [24-26], where they appear to activate and stabilize the SNARE complex in a fusion-ready state before calcium enters the terminal and binds to synaptotagmin (reviewed in [27]).…”

Section: Introductionmentioning

confidence: 99%

Enrichment and differential targeting of complexins 3 and 4 in ribbon-containing sensory neurons during zebrafish development

Zanazzi

Matthews

2010

Neural Dev

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BackgroundIn sensory systems with broad bandwidths, polarized receptor cells utilize highly specialized organelles in their apical and basolateral compartments to transduce and ultimately transmit signals to the rest of the nervous system. While progress has been made in elucidating the assembly of the transduction apparatus, the development of synaptic ribbon-containing terminals remains poorly understood. To begin to delineate the targeting of the exocytotic machinery specifically in ribbon-containing neurons, we have examined the expression of complexins 3 and 4 in the zebrafish visual and acousticolateral systems during the first week of development.ResultsWe have identified five members of the complexin 3/4 subfamily in zebrafish that show 50 to 75% amino acid identity with mammalian complexins 3 and 4. Utilizing a polyclonal antibody that recognizes all five orthologs, we demonstrate that these proteins are enriched in ribbon-containing sensory neurons. Complexin 3/4 is rapidly targeted to presynaptic terminals in the pineal organ and retina concomitantly with RIBEYE b, a component of ribbons. In hair cells of the inner ear and lateral line, however, complexin 3/4 immunoreactivity clusters on the apical surfaces of hair cells, among their stereocilia, rather than along the basolateral plasma membrane with RIBEYE b. A complexin 4a-specific antibody selectively labels the presynaptic terminals of visual system ribbon-containing neurons.ConclusionsThese results provide evidence for the concurrent transport and/or assembly of multiple components of the active zone in developing ribbon terminals. Members of the complexin 3/4 subfamily are enriched in these terminals in the visual system and in hair bundles of the acousticolateral system, suggesting that these proteins are differentially targeted and may have multiple roles in ribbon-containing sensory neurons.

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Identification of two highly homologous presynaptic proteins distinctly localized at the dendritic and somatic synapses

Cited by 101 publications

References 24 publications

Unique Structural Features of Membrane-Bound C-Terminal Domain Motifs Modulate Complexin Inhibitory Function

Unique Structural Features of Membrane-Bound C-Terminal Domain Motifs Modulate Complexin Inhibitory Function

Increased SNARE Protein-Protein Interactions in Orbitofrontal and Anterior Cingulate Cortices in Schizophrenia

Enrichment and differential targeting of complexins 3 and 4 in ribbon-containing sensory neurons during zebrafish development

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