Imai Akane, Nashida Tomoko, Yoshie Sumio, Shimomura Hiromi
Department of Biochemistry, School of Dentistry at Niigata, The Nippon Dental University, 1-8 Hamaura-cho, Niigata 951-8580, Japan.
Arch Oral Biol. 2003 Aug;48(8):597-604. doi: 10.1016/s0003-9969(03)00116-x.
Intracellular localisation of soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment protein receptors (SNAREs) is an important factor in clarifying whether SNAREs regulate exocytosis in salivary glands. We investigated intracellular localisation of syntaxins 2, 3 and 4 and SNAP-23, which are thought to be target membrane (t)-SNAREs, in rat parotid gland by Western blotting and immunocytochemistry. Syntaxins 2 and 3 were localised in the apical plasma membrane (APM), and syntaxin 4 was localised in the plasma membrane. SNAP-23 was localised in the APM and intracellular membrane (ICM). In a yeast two-hybrid assay, syntaxins 2, 3 and 4 interacted with SNAP-23 and VAMP-3. Using immunoprecipitation methods, syntaxins 3 and 4 were seen to interact with VAMP-8 and SNAP-23 at the APM, respectively. SNAP-23 interacted with syntaxin 3, syntaxin 4, VAMP-2, VAMP-3 and VAMP-8. Many SNARE complexes were detected under non-stimulated/basic conditions in the parotid APM. Some of these complexes may have a role in exocytosis from parotid acinar cells.
可溶性N - 乙基马来酰亚胺敏感融合蛋白（NSF）附着蛋白受体（SNAREs）的细胞内定位是阐明SNAREs是否调节唾液腺胞吐作用的一个重要因素。我们通过蛋白质免疫印迹法和免疫细胞化学方法，研究了大鼠腮腺中被认为是靶膜（t）-SNAREs的 syntaxin 2、3、4和SNAP - 23的细胞内定位。Syntaxin 2和3定位于顶端质膜（APM），syntaxin 4定位于质膜。SNAP - 23定位于APM和细胞内膜（ICM）。在酵母双杂交试验中，syntaxin 2、3和4与SNAP - 23和VAMP - 3相互作用。采用免疫沉淀法，可见syntaxin 3和4分别在APM处与VAMP - 8和SNAP - 23相互作用。SNAP - 23与syntaxin 3、syntaxin 4、VAMP - 2、VAMP - 3和VAMP - 8相互作用。在腮腺APM的非刺激/基础条件下检测到许多SNARE复合体。其中一些复合体可能在腮腺腺泡细胞的胞吐作用中发挥作用。
