Lledo P M, Vernier P, Vincent J D, Mason W T, Zorec R
Department of Neurobiology, AFRC Babraham Institute, Cambridge, UK.
Nature. 1993 Aug 5;364(6437):540-4. doi: 10.1038/364540a0.
Low-molecular-weight GTP-binding proteins (small G proteins) of the Rab family have been proposed to act as central regulators of vesicular traffic, and proteins of the Rab3 subfamily (Rab3A, B, C and D) are thought to be associated with membrane vesicles or granules undergoing exocytotic fusion with the plasma membrane. Rab3A is highly expressed in brain, whereas Rab3B is the major form found in rat anterior pituitary gland. We report here that antisense oligonucleotides against Rab3B, introduced into pituitary cells using the whole-cell patch clamp technique, specifically and reversibly block expression of Rab3B. We find that calcium-dependent exocytosis is inhibited without affecting endocytosis. Antisense oligonucleotides directed against Rab3A have no effect. Our results indicate that Rab3B is likely to be a key intracellular signalling molecule which can control exocytosis downstream of other calcium-dependent processes in anterior pituitary cells.
Rab家族的低分子量GTP结合蛋白（小G蛋白）被认为是囊泡运输的核心调节因子，Rab3亚家族的蛋白（Rab3A、B、C和D）被认为与经历与质膜胞吐融合的膜泡或颗粒相关。Rab3A在脑中高度表达，而Rab3B是大鼠垂体前叶中发现的主要形式。我们在此报告，使用全细胞膜片钳技术将针对Rab3B的反义寡核苷酸导入垂体细胞，可特异性且可逆地阻断Rab3B的表达。我们发现钙依赖性胞吐作用受到抑制，而内吞作用不受影响。针对Rab3A的反义寡核苷酸没有作用。我们的结果表明，Rab3B可能是一种关键的细胞内信号分子，可在前叶垂体细胞中其他钙依赖性过程的下游控制胞吐作用。
