Previous studies have shown that Prostaglandin E2 (PGE2) stimulates secretion of tick salivary gland proteins via a phosphoinositide signaling pathway and mobilization of intracellular Ca2+ (Qian et al., 1998; Yuan et al., 2000). Intracellular SNARE (soluble NSF attachment protein receptors) complex proteins associated with the mechanism of exocytotic protein secretion are highly conserved in vertebrate and invertebrate neuronal and nonneuronal cells. Our studies indicate that SNARE complex proteins are components of and likely involved in Ca2+ regulated protein secretion in tick salivary glands. Proteins in the salivary glands have been identified that cross-react individually with antibodies to vesicle (v)-SNARE (synaptobrevin 2), target (t)-SNARE (syntaxin 1A, syntaxin 2 and SNAP-25), cell trafficking a/b SNAP and NSF (N-ethylmaleimide-sensitive fusion protein), Ca2+ sensitive synaptotagmin and synaptophysin, and regulatory GTPase Rab3A and nSec1. v-SNARE and t-SNARE proteins form an SDS-resistant, boiling sensitive high molecular weight complex in the salivary glands. Results show that antibodies to SNARE complex proteins inhibit PGE2-stimulated secretion of anticoagulant protein in permeabilized tick salivary glands. We conclude that SNARE and cell trafficking regulatory proteins are present and necessary for the mechanism of PGE2-stimulated Ca2+ regulated protein secretion in tick salivary glands.
Species 1: Acari Ixodidae Amblyomma americanum (L.) (lone star tick)
Keywords: Salivary gland, SNARE
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA