To characterize the molecular mechanisms of platelet secretion, we focused on the calcium-induced exocytosis of dense core granules. Platelets contain several known t-SNAREs (soluble N-ethylmaleimide sensitive factor [NSF] attachment protein receptors) such as syntaxins 2, 4, and 7 and SNAP-23 (synaptosomal associated protein 23). By using an in vitro exocytosis assay, we have been able to assi...

SNAP-25 is an integral protein of the plasma membrane involved in neurotransmission and hormone secretion. The cysteine-rich domain of SNAP-25 is essential for membrane binding and plasma-membrane targeting. However, this domain is not required for SNARE complex formation and fusion of membranes in vitro. In this paper, we describe an 'intact-cell'-based system designed to compare the effect of...

Synaptosomal protein of 25 kDa (SNAP-25) is important for Ca(2+)-dependent fusion of large dense core vesicles (LDCVs) in insulin-secreting cells. Exocytosis is further enhanced by cAMP-increasing agents such as glucagon-like peptide-1 (GLP-1), and this augmentation includes interaction with both PKA and cAMP-GEFII. To investigate the coupling between SNAP-25- and cAMP-dependent stimulation of ...

At a synapse, the synaptic vesicle protein cysteine-string protein-a (CSPa) functions as a co-chaperone for the SNARE protein SNAP-25. Knockout (KO) of CSPa causes fulminant neurodegeneration that is rescued by a-synuclein overexpression. The CSPa KO decreases SNAP-25 levels and impairs SNARE-complex assembly; only the latter but not the former is reversed by a-synuclein. Thus, the question ari...

Previously we reported that SNAP-25, synaptobrevin II, and syntaxin I, the intracellular substrates of botulinum toxin originally identified in nontarget tissues, were present in a recognized mammalian target tissue, the mouse hemidiaphragm. Furthermore, we reported that SNAP-25, syntaxin I, and synaptobrevin II were cleaved by incubation of the intact hemidiaphragm in botulinum serotypes A, C,...

Among carnivorous plants, Darwin was particularly fascinated by the speed and sensitivity of snap-traps in Dionaea and Aldrovanda. Recent molecular work confirms Darwin's conjecture that these monotypic taxa are sister to Drosera, meaning that snap-traps evolved from a 'flypaper' trap. Transitions include tentacles being modified into trigger hairs and marginal 'teeth', the loss of sticky tenta...