Identification of nicotinic acetylcholine receptor recycling and its role in maintaining receptor density at the neuromuscular junction in vivo.
AuthorsBruneau E, Sutter D, Hume RI, Akaaboune M
JournalJ Neurosci
PubMed ID16251443
'In the CNS, receptor recycling is critical for synaptic plasticity; however, the recycling of receptors has never been observed at peripheral synapses. Using a novel imaging technique, we show here that nicotinic acetylcholine receptors (AChRs) recycle into the postsynaptic membrane of the neuromuscular junction. By sequentially labeling AChRs with biotin-bungarotoxin ... More
Precise localization of alpha7 nicotinic acetylcholine receptors on glutamatergic axon terminals in the rat ventral tegmental area.
AuthorsJones IW, Wonnacott S
JournalJ Neurosci
PubMed ID15601930
'Alpha7 neuronal nicotinic acetylcholine receptors (nAChRs) constitute one of the predominant nAChR subtypes in the mammalian brain. Within the ventral tegmental area (VTA), nicotine application, paired with postsynaptic stimulation, contributes to a form of long-term potentiation, an effect attributed to presynaptic alpha7 nAChRs on glutamatergic afferents (Mansvelder and McGehee, 2000). ... More
Imaging of receptor trafficking by using alpha-bungarotoxin-binding-site-tagged receptors.
AuthorsSekine-Aizawa Y, Huganir RL,
JournalProc Natl Acad Sci U S A
PubMed ID15563595
'alpha-Amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) receptors mediate excitatory synaptic transmission and are dynamically regulated during synaptic plasticity in the CNS. The membrane trafficking of AMPA receptors to synapses is critical for the regulation of the efficacy of excitatory synaptic transmission. Direct imaging of AMPA receptors in various cell compartments is important to dissecting ... More
Erratic deposition of agrin during the formation of Xenopus neuromuscular junctions in culture.
AuthorsAnderson MJ, Shi ZQ, Grawel R, Zackson SL
JournalDev Biol
PubMed ID7601300
'In order to disclose the mechanism that regulate synapse development we compared the distributions of agrin, acetylcholine receptors (AChR) and a basal lamina heparan sulfate proteoglycan (HSPG) in sections and cultures prepared from Xenopus laevis and Ambystoma mexicanum embryos. While agrin, AChR and HSPG may accumulate almost synchronously at synapses ... More
The agrin receptor. Localization in the postsynaptic membrane, interaction with agrin, and relationship to the acetylcholine receptor.
AuthorsMa J, Nastuk MA, McKechnie BA, Fallon JR
JournalJ Biol Chem
PubMed ID8227074
'Agrin is a component of the synaptic basal lamina that induces the aggregation of acetylcholine receptors (AChRs) and other elements of the postsynaptic membrane. We have determined the localization, binding characteristics, and biochemical profile of the agrin receptor in Torpedo electric organ membranes and defined domains of agrin that bind ... More
'Agrin is an extracellular matrix protein that directs neuromuscular junction formation. Early signal transduction events in agrin-mediated postsynaptic differentiation include activation of a receptor tyrosine kinase and phosphorylation of acetylcholine receptors (AChRs), but later steps in this pathway are unknown. Here, we have investigated the role of intracellular calcium in ... More
Agrin induces phosphorylation of the nicotinic acetylcholine receptor.
AuthorsWallace BG, Qu Z, Huganir RL
JournalNeuron
PubMed ID1711347
'Agrin causes acetylcholine receptors (AChRs) on chick myotubes in culture to aggregate, forming specializations that resemble the postsynaptic apparatus at the vertebrate skeletal neuromuscular junction. Here we report that treating chick myotubes with agrin caused an increase in phosphorylation of the AChR beta, gamma, and delta subunits. H-7, a potent ... More
Agrin-induced phosphorylation of the acetylcholine receptor regulates cytoskeletal anchoring and clustering.
AuthorsBorges LS, Ferns M
JournalJ Cell Biol
PubMed ID11285269
'At the developing neuromuscular junction, a motoneuron-derived factor called agrin signals through the muscle-specific kinase receptor to induce postsynaptic aggregation of the acetylcholine receptor (AChR). The agrin signaling pathway involves tyrosine phosphorylation of the AChR beta subunit, and we have tested its role in receptor localization by expressing tagged, tyrosine-minus ... More
Crosslinkage and visualization of acetylcholine receptors on myotubes with biotinylated alpha-bungarotoxin and fluorescent avidin.
AuthorsAxelrod D
JournalProc Natl Acad Sci U S A
PubMed ID6933533
'A biotinylated derivative of alpha-bungarotoxin and tetramethylrhodamine-labeled avidin were employed to fluorescence label the acetylcholine receptors (AcChoR) on the surface of rat myotubes in primary culture. Because of the multivalency of both the biotinylated bungarotoxin and the avidin, this treatment extensivey crosslinks the AcChoR. AcChoR crosslinking immobilizes more than 90% ... More
The formation of acetylcholine receptor clusters visualized with quantum dots.
AuthorsGeng L, Zhang HL, Peng HB,
JournalBMC Neurosci
PubMed ID19604411
BACKGROUND: Motor innervation of skeletal muscle leads to the assembly of acetylcholine receptor (AChR) clusters in the postsynaptic membrane at the vertebrate neuromuscular junction (NMJ). Synaptic AChR aggregation, according to the diffusion-mediated trapping hypothesis, involves the establishment of a postsynaptic scaffold that ... More
Quantum dot ex vivo labeling of neuromuscular synapses.
Nicotinic receptors (nAchRs) are responsible for fast excitatory signaling by the neurotransmitter acetylcholine (Ach). They are present on the postsynaptic membrane at neuromuscular junctions (NMJs) and also at brain synapses. Alpha-bungarotoxin (alpha-BTX), a high-affinity nAchR antagonist, inhibits Ach binding and neurotransmission. Here we demonstrate biotinylated alpha-BTX, bound to native mouse ... More
One of the important events in synapse formation is the accumulation of neurotransmitter receptors beneath the presynaptic nerve terminal. Agrin is a component of the synaptic basal lamina that induces the clustering of acetylcholine receptors when bath-applied to muscle fibers in culture. When a cDNA encoding a putative agrin protein ... More
alpha-Actinin interacts with rapsyn in agrin-stimulated AChR clustering.
AuthorsDobbins GC, Luo S, Yang Z, Xiong WC, Mei L,
JournalMol Brain
PubMed ID19055765
: AChR is concentrated at the postjunctional membrane at the neuromuscular junction. However, the underlying mechanism is unclear. We show that alpha-actinin, a protein known to cross-link F-actin, interacts with rapsyn, a scaffold protein essential for neuromuscular junction formation. alpha-Actinin, rapsyn, and surface AChR form a ternary complex. Moreover, the ... More
An ELISA for the detection of anti-acetylcholine receptor antibodies using biotinylated alpha-bungarotoxin.
AuthorsQuinn A, Harrison R, Jehanli AM, Lunt GG, Walsh S
JournalJ Immunol Methods
PubMed ID3346551
An antibody-capture enzyme immunoassay has been developed for the detection of anti-acetylcholine receptor (AChR) antibodies in tissue culture supernatants using biotinylated alpha-bungarotoxin (B alpha BGT). Immunoglobulins in culture supernatants were bound indirectly to microtitre plates via an anti-globulin antibody already coupled to polyvinyl plates. Anti-AChR antibodies were then detected by ... More
Identification of a motif in the acetylcholine receptor beta subunit whose phosphorylation regulates rapsyn association and postsynaptic receptor localization.
At the neuromuscular junction, the acetylcholine receptor (AChR) is specifically clustered in the postsynaptic membrane via interactions with rapsyn and other scaffolding proteins. However, it remains unclear where these proteins bind on the AChR and how the interactions are regulated. Here, we define a phosphorylation-dependent binding site on the receptor ... More
Neurotransmitter receptor dynamics studied in vivo by reversible photo-unbinding of fluorescent ligands.
AuthorsAkaaboune M, Grady RM, Turney S, Sanes JR, Lichtman JW
JournalNeuron
PubMed ID12086635
We show that fluorescently tagged ligands with high affinity for their targets can be reversibly unbound by focused laser excitation. By sequential unbinding and relabeling with different colors of alpha-bungarotoxin, we selectively labeled adjacent pools of acetylcholine receptors (AChRs) at neuromuscular junctions of adult mice. Timelapse imaging in vivo revealed ... More
Nicotinic acetylcholine receptor is internalized via a Rac-dependent, dynamin-independent endocytic pathway.
AuthorsKumari S, Borroni V, Chaudhry A, Chanda B, Massol R, Mayor S, Barrantes FJ,
JournalJ Cell Biol
PubMed ID18591431
Endocytosis of the nicotinic acetylcholine receptor (AChR) is a proposed major mechanism of neuromodulation at neuromuscular junctions and in the pathology of synapses in the central nervous system. We show that binding of the competitive antagonist alpha-bungarotoxin (alphaBTX) or antibody-mediated cross-linking induces the internalization of cell surface AChR to late ... More
Absence of alpha-syntrophin leads to structurally aberrant neuromuscular synapses deficient in utrophin.
The syntrophins are a family of structurally related proteins that contain multiple protein interaction motifs. Syntrophins associate directly with dystrophin, the product of the Duchenne muscular dystrophy locus, and its homologues. We have generated alpha-syntrophin null mice by targeted gene disruption to test the function of this association. The alpha-Syn(-/)- ... More
Staurosporine inhibits agrin-induced acetylcholine receptor phosphorylation and aggregation.
AuthorsWallace BG
JournalJ Cell Biol
PubMed ID7513708
Agrin, a protein that mediates nerve-induced acetylcholine receptor (AChR) aggregation at developing neuromuscular junctions, has been shown to cause an increase in phosphorylation of the beta, gamma, and delta subunits of AChRs in cultured myotubes. As a step toward understanding the mechanism of agrin-induced AChR aggregation, we examined the effects ... More
Laminin-1 redistributes postsynaptic proteins and requires rapsyn, tyrosine phosphorylation, and Src and Fyn to stably cluster acetylcholine receptors.
AuthorsMarangi PA, Wieland ST, Fuhrer C
JournalJ Cell Biol
PubMed ID12034776
Clustering of acetylcholine receptors (AChRs) is a critical step in neuromuscular synaptogenesis, and is induced by agrin and laminin which are thought to act through different signaling mechanisms. We addressed whether laminin redistributes postsynaptic proteins and requires key elements of the agrin signaling pathway to cause AChR aggregation. In myotubes, ... More
Tyrosine phosphorylation and acetylcholine receptor cluster formation in cultured Xenopus muscle cells.
AuthorsBaker LP, Peng HB
JournalJ Cell Biol
PubMed ID7678011
Aggregation of the nicotinic acetylcholine receptor (AChR) at sites of nerve-muscle contact is one of the earliest events to occur during the development of the neuromuscular junction. The stimulus presented to the muscle by nerve and the mechanisms underlying postsynaptic differentiation are not known. The purpose of this study was ... More
Immobilization of nicotinic acetylcholine receptors in mouse C2 myotubes by agrin-induced protein tyrosine phosphorylation.
AuthorsMeier T, Perez GM, Wallace BG
JournalJ Cell Biol
PubMed ID7593170
Agrin induces the formation of highly localized specializations on myotubes at which nicotinic acetylcholine receptors (AChRs) and many other components of the postsynaptic apparatus at the vertebrate skeletal neuromuscular junction accumulate. Agrin also induces AChR tyrosine phosphorylation. Treatments that inhibit tyrosine phosphorylation prevent AChR aggregation. To examine further the relationship ... More
Purification and characterization of a polypeptide from chick brain that promotes the accumulation of acetylcholine receptors in chick myotubes.
AuthorsUsdin TB, Fischbach GD
JournalJ Cell Biol
PubMed ID3733876
Acetylcholine receptors (AChRs) are packed in the postsynaptic membrane at neuromuscular junctions at a density of approximately 20,000/micron 2, whereas the density a few micrometers away is less than 20/micron 2. To understand how this remarkable distribution comes about during nerve-muscle synapse formation, we have attempted to isolate factors from ... More
Localized force application reveals mechanically sensitive domains of Piezo1.
Authors
JournalNat Commun
PubMed ID27694883
Neuronal mechanisms of respiratory pattern generation are evolutionary conserved.
Authors
JournalJ Neurosci
PubMed ID23699521
Neuroprotective effects of violacein in a model of inherited amyotrophic lateral sclerosis.
Authors
JournalSci Rep
PubMed ID35292673
Combining timed GDNF and ChABC gene therapy to promote long-distance regeneration following ventral root avulsion and repair.
Authors
JournalFASEB J
PubMed ID32543730
A mechanism in agrin signaling revealed by a prevalent Rapsyn mutation in congenital myasthenic syndrome.
Authors
JournalElife
PubMed ID31549961
Progress of endocytic CHRN to autophagic degradation is regulated by RAB5-GTPase and T145 phosphorylation of SH3GLB1 at mouse neuromuscular junctions in vivo.
Authors
JournalAutophagy
PubMed ID27715385
Liprin-α-1 is a novel component of the murine neuromuscular junction and is involved in the organization of the postsynaptic machinery.
Authors
JournalSci Rep
PubMed ID28831123
Drebrin Regulates Acetylcholine Receptor Clustering and Organization of Microtubules at the Postsynaptic Machinery.
Authors
JournalInt J Mol Sci
PubMed ID34502296
A novel bungarotoxin binding site-tagged construct reveals MAPK-dependent Kv4.2 trafficking.
Authors
JournalMol Cell Neurosci
PubMed ID31212013
Role of autophagy, SQSTM1, SH3GLB1, and TRIM63 in the turnover of nicotinic acetylcholine receptors.