Localization of SNARE proteins in the brain and corpus allatum of Bombyx mori

Abstract

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) comprise the core machinery that mediates membrane fusion. SNAREs, syntaxin, synaptosome-associated protein (SNAP), and synaptobrevin form a tight SNARE complex that brings the vesicle and plasma membranes together and is essential for membrane fusion. The cDNAs of SNAP-25, VAMP2, and Syntaxin 1A from Bombyx mori were inserted into a plasmid, transformed into Escherichia coli, and purified. We then produced antibodies against the SNAP-25, VAMP2, and Syntaxin 1A of Bombyx mori of rabbits and rats, which were used for immunohistochemistry. Immunohistochemistry results revealed that the expression of VAMP2 was restricted to neurons in the pars intercerebralis, dorsolateral protocerebrum, and central complex of the brain. SNAP-25 was restricted to neurons in the pars intercerebralis and the central complex of the brain. Syntaxin 1A was restricted to neurons in the pars intercerebralis and dorsolateral protocerebrum of the brain. SNAP-25 colocalizes with VAMP2 in the central complex and Syntaxin 1A colocalizes with bombyxin, which is an insect neuropeptide. These findings suggest that SNARE proteins play important roles in membrane trafficking in the insect brain.