syntaxin, syx, syx-1A, Syx1, syntaxin1
vesicular docking protein - a t-SNARE - involved in docking and fusion of neurotransmitter-filled vesicles with the presynaptic membrane to release neurotransmitter into the synaptic cleft - organized in nanoclusters that are critical for the docking and priming of secretory vesicles from neurosecretory cells
Gene model reviewed during 5.49
Shares 3' UTR sequences with upstream gene.
Multiphase exon postulated: this gene shares a region of coding sequence with an overlapping gene, but different reading frames are utilized in the overlapping coding region.
Gene model reviewed during 6.04
12, 9, 8, 7, 4.4, 3.5 (northern blot)
291 (aa); 35 (kD observed)
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Syx1A using the Feature Mapper tool.
In situ hybridization reveals that Syx1A transcripts are present throuhgout precellularized embryos though they are most prevalent at the posterior pole. After cellularization, Syx1A transcripts are present in all cells and appear to be concentrated near the cell membrane. In stage 9 embryos, transcripts are observed in the anterior and posterior midgut invaginations as well as in the ventral neuroblasts and the ectoderm.
Syx1A transcripts are expressed in a complex pattern throughout development. Up to six transcripts are observed at any given stage on northern blots. In early embryos, the 3.5, 4.2, and 8.0kb transcripts are abundant. In 3-9hr embryos, the 4.2, 8.0, and 9.0kb transcripts predominate. The 7.0 and 12.0kb transcripts appear after 9hr. In first instar larvae, 5 transcripts are prominent. In second and third instar larvae, the number of abundant transcripts is reduced to three and two, respectively. During pupation, 5 transcripts reappear and are also seen in adults.
Syx1A expression is widespread in the embryo prior to stage 12. After this, expression in ectodermal cells has faded and expression is observed mainly in the anterior and posterior midguts, the garland cells, and the CNS. By stage 14, the major sites of expression are the CNS and the garland cells. Weaker expression is observed in the PNS.
Syx1A protein is detected in germarium regions 2 and 3 outlining the membranes of the cyst cells. It continues to be abundantly expressed in the nurse cells during oogenesis stages S1-S8. Levels fade during stages S8 and S9. In early embryos, Syx1A protein is present ubiquitously but is concentrated at the posterior tip where it accumulates under the pole buds. At mitotic cycle 13, the protein is concentrated in hexagonal-shaped outlines that correspond to the cleavage furrows of the cytoplasmic buds. After cellularization it is present in all of the membranes of all cells. During germband extension, it is present in the mesoderm, ectoderm, and invaginating neurectoderm but is excluded from the amnioserosa. Syx1A protein is also present in the adult brain and the synaptic substations of the visual system. In the brain it is concentrated in neuropil regions and is somewhat enriched at synaptic regions such as the lamina and the medulla.
Syx1A protein is enriched in neuromuscular junction synaptic boutons, but is also expressed at high levels throughout the axons of the peripheral nerves.
syx1a protein is present primarily in the CNS and garland cells though some staining is seen in the ectoderm and the midgut in stages 15-17. In the CNS, staining is most prominent along the longitudinal tracts of the ventral nerve cord and brain but is also found in the commissures of the CNS and the axons of the peripheral nerves. In the periphery of the embryo, staining is seen in neuromuscular junctions and at low levels in some cell bodies.
GBrowse - Visual display of RNA-Seq signalsView Dmel\Syx1A in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Source for identity of: syx1A CG5448
Source for merge of Syx1A anon- EST:Gibbs4 was sequence comparison ( date:030707 ).
Source for merge of syx1A CG18615 was sequence comparison ( date:001104 ).
Source for merge of Syx1A anon-WO02059370.54 was sequence comparison ( date:051113 ).
Source for merge of Syx1A CG10716 was a shared cDNA ( date:010720 ).
dsRNA made from templates generated with primers directed against this gene was tested in an RNAi screen to identify genes that regulate Ca2+ release.
dsRNA directed against this gene causes defects in cytokinesis when tested in an RNAi screen in S2 cells.
Syx1A gene product interacts with multiple exocytic proteins to regulate neurotransmitter release in vivo.
Germline clonal analysis reveals Syx1A is required in the female germline for oocyte development. Syx1A is required for cell viability in the eye, during wing development and plays a role in membranes of the nervous system.
Syx1A is absolutely required for spontaneous vesicle fusions, for these events are absent in Syx1A null mutants. However, mature, docked synaptic vesicles are observed by EM at release sites in the presynaptic terminals of Syx1A mutant synapses. Therefore, SYX1A functions downstream of vesicle docking and participates in fusion.
Identified and cloned using the monoclonal antibody mAb44D5. The protein is localised in the synaptic areas of the CNS and at neuromuscular junctions.