Arg206 of SNAP-25 is essential for neuroexocytosis at the <i>Drosophila melanogaster</i> neuromuscular junction

Megighian, Aram; Scorzeto, Michele; Zanini, Damiano; Pantano, Sergio; Rigoni, Michela; Benna, Clara; Rossetto, Ornella; Montecucco, Cesare; Zordan, Mauro Agostino

doi:10.1242/jcs.071316

Cited by 19 publications

(12 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Oligomerization of SNAREs may be induced by TMD (227,255,335,342), SNARE motifs (409,593), or complexin (644). Recent liposome experiments demonstrate that SNAREs form zig zag-shaped oligomers with the help of complexin (294,334,354).…”

Section: Snare Oligomerizationmentioning

confidence: 99%

Distinct Initial SNARE Configurations Underlying the Diversity of Exocytosis

Kasai

Takahashi

Tokumaru

2012

Physiological Reviews

143

124

View full text Add to dashboard Cite

The dynamics of exocytosis are diverse and have been optimized for the functions of synapses and a wide variety of cell types. For example, the kinetics of exocytosis varies by more than five orders of magnitude between ultrafast exocytosis in synaptic vesicles and slow exocytosis in large dense-core vesicles. However, in all cases, exocytosis is mediated by the same fundamental mechanism, i.e., the assembly of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. It is often assumed that vesicles need to be docked at the plasma membrane and SNARE proteins must be preassembled before exocytosis is triggered. However, this model cannot account for the dynamics of exocytosis recently reported in synapses and other cells. For example, vesicles undergo exocytosis without prestimulus docking during tonic exocytosis of synaptic vesicles in the active zone. In addition, epithelial and hematopoietic cells utilize cAMP and kinases to trigger slow exocytosis of nondocked vesicles. In this review, we summarize the manner in which the diversity of exocytosis reflects the initial configurations of SNARE assembly, including trans-SNARE, binary-SNARE, unitary-SNARE, and cis-SNARE configurations. The initial SNARE configurations depend on the particular SNARE subtype (syntaxin, SNAP25, or VAMP), priming proteins (Munc18, Munc13, CAPS, complexin, or snapin), triggering proteins (synaptotagmins, Doc2, and various protein kinases), and the submembraneous cytomatrix, and they are the key to determining the kinetics of subsequent exocytosis. These distinct initial configurations will help us clarify the common SNARE assembly processes underlying exocytosis and membrane trafficking in eukaryotic cells.

show abstract

Section: Snare Oligomerizationmentioning

confidence: 99%

Distinct Initial SNARE Configurations Underlying the Diversity of Exocytosis

Kasai

Takahashi

Tokumaru

2012

Physiological Reviews

143

124

View full text Add to dashboard Cite

show abstract

“…and syntaxin isoforms [syntaxin D253R and syntaxin WT ] were produced by PCR using primers carrying point mutations as necessary. The general strategy is the one used before (Megighian et al, 2010). The ORFs encoding for SNAP-25 and for syntaxin were amplified from the full-length cDNA derived from w 1118 flies using the primer pairs listed below.…”

Section: R198dmentioning

confidence: 99%

Evidence for a radial SNARE super-complex mediating neurotransmitter release at the Drosophila neuromuscular junction

Megighian

Zordan

Pantano

et al. 2013

Journal of Cell Science

Self Cite

View full text Add to dashboard Cite

SummaryThe SNARE proteins VAMP/synaptobrevin, SNAP-25 and syntaxin are core components of the apparatus that mediates neurotransmitter release. They form a heterotrimeric complex, and an undetermined number of SNARE complexes assemble to form a super-complex. Here, we present a radial model of this nanomachine. Experiments performed with botulinum neurotoxins led to the identification of one arginine residue in SNAP-25 and one aspartate residue in syntaxin (R206 and D253 in Drosophila melanogaster). These residues are highly conserved and predicted to play a major role in the protein-protein interactions between SNARE complexes by forming an ionic couple. Accordingly, we generated transgenic Drosophila lines expressing SNAREs mutated in these residues and performed an electrophysiological analysis of their neuromuscular junctions. Our results indicate that SNAP-25-R206 and syntaxin-D253 play a major role in neuroexocytosis and support a radial assembly of several SNARE complexes interacting via the ionic couple formed by these two residues.

show abstract

“…A mature granule fuses with a unit granule (to grow into a bigger granule) or with the cell's membrane (to exit the cell) via the formation of a circular rosette [11] composed of SNARE proteins [24 -31]. The selfaggregation capacity of the SNARE protein complex has been reported [26][27][28]31,36], whereby each unit granule has a limited number of 'hooks' and the target membranes have a limited number of 'loops'. For example, in SVs, the hook is one t-SNARE (SNAP-25 þ syntaxin complex), the loop is one v-SNARE (VAMP protein), and a SNARE pair is a complex of one t-SNARE and one v-SNARE [28].…”

Section: Quantal Basis Of Vesicle Growth and Information Contentmentioning

confidence: 99%

Function suggests nano-structure: electrophysiology supports that granule membranes play dice

Hammel

Meilijson

2012

J. R. Soc. Interface.

View full text Add to dashboard Cite

Cellular communication depends on membrane fusion mechanisms. SNARE proteins play a fundamental role in all intracellular fusion reactions associated with the life cycle of secretory vesicles, such as vesicle -vesicle and vesicle plasma membrane fusion at the porosome base in the cell plasma membrane. We present growth and elimination (G&E), a birth and death model for the investigation of granule growth, its evoked and spontaneous secretion and their information content. Using a statistical mechanics approach in which SNARE components are viewed as interacting particles, the G&E model provides a simple 'nanomachine' of SNARE self-aggregation behind granule growth and secretion. Results from experimental work, mathematical calculations and statistical modelling suggest that for vesicle growth a minimal aggregation of three SNAREs is required, while for the evoked secretion one SNARE is enough. Furthermore, the required number of SNARE aggregates (which varies between cell types and is nearly proportional to the square root of the mean granule diameter) affects and is statistically identifiable from the size distributions of spontaneous and evoked secreted granules. The new statistical mechanics approach to granule fusion is bound to have a significant changing effect on the investigation of the pathophysiology of secretory mechanisms and methodologies for the investigation of secretion.

show abstract

Arg206 of SNAP-25 is essential for neuroexocytosis at the Drosophila melanogaster neuromuscular junction

Cited by 19 publications

References 63 publications

Distinct Initial SNARE Configurations Underlying the Diversity of Exocytosis

Distinct Initial SNARE Configurations Underlying the Diversity of Exocytosis

Evidence for a radial SNARE super-complex mediating neurotransmitter release at the Drosophila neuromuscular junction

Function suggests nano-structure: electrophysiology supports that granule membranes play dice

Contact Info

Product

Resources

About