Roles of Munc18-3 in amylase release from rat parotid acinar cells
Roles of Munc18-3 in amylase release from rat parotid acinar cells
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DOI：
10.1016/j.abb.2003.12.021
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发表时间：
2004-02-15
影响因子：
3.9
通讯作者：
Shimomura, H
中科院分区：
文献类型：
--
作者：
Imai, A;Nashida, T;Shimomura, H
已经在大鼠腮腺腺泡细胞中鉴定了几种“可溶性N-乙基马来酰亚胺敏感性融合蛋白附着蛋白受体”（SNARE）蛋白，包括VAMP-2、突触融合蛋白4和SNAP-23。此外，已经报道了Munc 18 c（Munc 183）和syntaxin 4之间的关联。然而，Munc 18-3在腮腺腺泡细胞分泌颗粒胞吐中的作用仍不清楚。在本研究中，我们研究了Munc 18 -3在大鼠腮腺腺泡细胞中的作用。Muncl 8 -3定位于胞吐作用发生的顶端质膜上，并与突触融合蛋白4相互作用。抗Munc 18 -3抗体剂量依赖性地减少异丙肾上腺素（IPR）诱导的淀粉酶从SLO透化的腮腺腺泡细胞释放。此外，刺激的腺泡细胞与IPR诱导Munc 18 -3从质膜易位到胞质溶胶。Munc-18-3不被蛋白激酶（PK）A的催化亚基磷酸化，而是被PKC磷酸化。用PKC而不是PKA处理质膜诱导Munc 18 -3从膜上移位。结果表明，Munc 18 -3调节胞吐在腺泡细胞的IPR诱导的淀粉酶的释放和蛋白激酶A的Munc 18 -3的磷酸化是不参与的机制。(C)2003年爱思唯尔公司All rights reserved.
Several "soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor" (SNARE) proteins have been identified in rat parotid acinar cells, including VAMP-2, syntaxin 4, and SNAP-23. Furthermore, an association between Munc 18c (Munc 183) and syntaxin 4 has been reported. However, the role of Munc 18-3 in secretory granule exocytosis on parotid acinar cells remains unclear. In the present study, we investigated the role of Munc18-3 in rat parotid acinar cells. Muncl8-3 was localized on the apical plasma membrane where exocytosis occurs and interacted with syntaxin 4. Anti-Munc18-3 antibody dose-dependently decreased isoproterenol (IPR)-induced amylase release from SLO-permeabilized parotid acinar cells. Furthermore, stimulation of the acinar cells with IPR induced translocation of Munc18-3 from the plasma membrane to the cytosol. Munc-18-3 was not phosphorylated by a catalytic subunit of protein kinase (PK) A but phosphorylated by PKC. Treatment of,the plasma membrane with PKC but not PKA induced displacement of Munc18-3 from the membrane. The results indicate that Munc18-3 regulates exocytosis in the acinar cells for IPR-induced amylase release and that phosphorylation of Munc18-3 by PKA is not involved in the mechanism. (C) 2003 Elsevier Inc. All rights reserved.