Syntaxins are membrane proteins involved in vesicle trafficking and are required for the release of neurotransmitter at nerve terminals. fails entirely within these regions. These results provide genetic evidence that membrane trafficking is required for the cellularization of the syncytial blastoderm. We propose that MK-2206 2HCl manufacturer the invagination MK-2206 2HCl manufacturer of the surface membrane proceeds by the fusion of intracellular membrane vesicles with the surface. This reaction uses the same syntaxin1 protein as is required for neurotransmitter secretion at synapses. Therefore, a single syntaxin can participate in trafficking methods that are functionally as unique as synaptic transmission and cell division. The movement of membranes within a cell via transport vesicles is necessary for many cellular events, ranging from intracellular transport and constitutive secretion to the tightly regulated secretion of transmitter at nerve terminals (Bennett and Scheller, 1993). The molecular mechanisms underlying all such vesicle trafficking look like analogous, involving specific protein-mediated interactions between the transport vesicle and the acceptor membrane (Rothman and Wieland, 1996). Syntaxins and related proteins that are collectively referred to as t-SNAREs reside on target membranes and are hypothesized to serve as address labels that determine a membrane compartment (for review observe Sollner and Rothman, 1994). MK-2206 2HCl manufacturer Relating to this hypothesis, the specificity of vesicular focusing on arises from the connection of a t-SNARE with its counterpart v-SNARE within the transport vesicle. In candida, homologues of syntaxins are necessary for ER to Golgi (Hardwick and Pelham, 1992), Golgi to plasma membrane (Aalto et al., 1993), and vacuolar trafficking (Piper et al., 1994). In nerve terminals, syntaxins are present within the presynaptic membrane and are recognized to interact with other proteins implicated in vesicular launch (Bennett et al., 1992; for review observe Sudhof, 1995). The counterpart v-SNARE for syntaxin is the synaptic vesicle protein synaptobrevin, also called VAMP, which has been shown to bind MK-2206 2HCl manufacturer syntaxin (Calakos et al., 1994). Another vesicular protein, synaptotagmin, also binds to syntaxin (Kee and Scheller, 1996), as does the plasma membrane protein SNAP-25 and the cytosolic protein nsec1 (Pevsner et al., 1994). Additional cytosolic factors including NSF and , , and Snap can also be found in a larger complex comprising syntaxin (Sollner et al., 1993homologue referred to as (abolishes synaptic transmission; release could not become evoked by either electrical stimulation or black widow spider venom, and spontaneous vesicle fusions were absent (Broadie et al., 1995; Schulze et al., 1995). Additional secretion phenotypes, such as a smooth cuticle and undigested yolk, were also reported in the mutants (Schulze et al., 1995). Interestingly, the genetic removal of did not disrupt the ability of vesicles to be targeted to and morphologically docked in the nerve terminal membrane (Broadie et al., 1995). Therefore, although this protein is clearly essential for synaptic transmission, its exact part in the focusing on and fusion of vesicles remains uncertain. While analyzing transcripts from your gene, we observed the presence of PTGS2 MK-2206 2HCl manufacturer message at the earliest stages of development, in embryos 3 h older (Parfitt et al., 1995). The presence of transcript at these times, when no neurons have differentiated and the cuticle has not yet been secreted, suggested a new and unique part for in development. A potential maternal contribution of mRNA is definitely suggested from the transcript analysis, and therefore, the importance of in early development.