The first step in transepithelial sodium absorption lies at the apical membrane where the amiloride-sensitive, epithelial sodium channel, ENaC, facilitates sodium entry into the cell. Here we report that the vesicle traffic regulatory (SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)) protein, syntaxin 1A (S1A), inhibits ENaC mediated sodium entry. This inhibitory e...

Syntaxin is a key presynaptic protein that binds to N- and P/Q-type Ca(2+) channels in biochemical studies and affects gating of these Ca(2+) channels in expression systems and in synaptosomes. The present study was aimed at understanding the molecular basis of syntaxin modulation of N-type channel gating. Mutagenesis of either syntaxin 1A or the pore-forming alpha(1B) subunit of N-type Ca(2+) ...

The neuronal acceptor SNARE complex that functions as the receptor for synaptic vesicle docking and fusion at the presynaptic membrane is composed of the single-span transmembrane protein syntaxin-1A and the palmitoylated soluble protein SNAP-25. Previously, we explored interactions that promote the formation of syntaxin-1A clusters in membranes. Cholesterol activates clustering in native and m...

The target-SNARE syntaxin 1A is an essential component of the core machinery required for regulated exocytosis (where SNARE is the soluble N-ethylmaleimide-sensitive fusion protein-attachment protein receptor). Syntaxin 1A interacts with a variety of other proteins, two of which, N-ethylmaleimide-sensitive fusion protein (NSF) and alpha-soluble NSF attachment protein (alpha-SNAP) have been sugg...

We have hypothesized that the plasma membrane protein components of the exocytotic soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor (SNARE) complex, syntaxin 1A and SNAP-25, distinctly regulate different voltage-gated K+ (Kv) channels that are differentially distributed. Neuroendocrine islet cells (alpha, beta, delta) uniformly contain both syntaxin 1A and SNAP-25. H...

Syntaxins are target-soluble N-ethylmaleimide-sensitive factor-attachment protein receptors (t-SNAREs) involved in docking and fusion of vesicles in exocytosis and endocytosis. Many syntaxin isoforms have been isolated, and each one displays a distinct intracellular localization pattern. However, the signals that drive the specific intracellular localization of syntaxins are poorly understood. ...

To further characterize the molecular mechanisms of platelet function, we have sought to identify some of the proteins that mediate the secretory events of the platelet release reaction. We report that platelets contain the general elements of the membrane transport apparatus: N-ethylmaleimide sensitive fusion protein (NSF), p115/transcytosis-associated protein (p115/TAP), and the soluble NSF a...

Interaction of syntaxin 1 with the a1D subunit of the voltage-gated L type Ca21 channel was investigated in the pancreatic b cell. Coexpression of the enhanced green fluorescent protein-linked a1D subunit with the enhanced blue f luorescent protein-linked syntaxin 1 and Western blot analysis together with subcellular fractionation demonstrated that the a1D subunit and syntaxin 1 were colocalize...

The assembly of lipid droplets is dependent on PtdIns(4,5)P(2) that activates PLD(1) (phospholipase D(1)), which is important for the assembly process. ERK2 (extracellular-signal-regulated kinase 2) phosphorylates the motor protein dynein and sorts it to lipid droplets, allowing them to be transported on microtubules. Lipid droplets grow in size by fusion, which is dependent on dynein and the t...