Differential dynamics of Rab3A and Rab27A on secretory granules.
Differential dynamics of Rab3A and Rab27A on secretory granules.
复制标题
DOI：
10.1242/jcs.03406
复制
发表时间：
2007-03-15
影响因子：
4
通讯作者：
Burgoyne RD
中科院分区：
文献类型：
--
作者：
Handley MT;Haynes LP;Burgoyne RD
我们已经评估了Rab 3A和Rab 27 A与分泌颗粒在PC 12细胞中的各个生命阶段的关联的动力学。内源性Rab 3A与分泌颗粒标记物分泌颗粒蛋白II（SGII）共定位，并表达EGFP-Rab 3A和ECFP-Rab 27 A相互共定位。EGFP-Rab 3A或EGFP-Rab 27和SGII之间的共定位的程度在转染后较长时间后增加，这表明这些Rab蛋白优先被募集到新合成的颗粒中。在未成熟的分泌颗粒从trans-Golgi网络释放后，Rab 3A和Rab 27 A在约20分钟的滞后期后与未成熟的颗粒结合。在光漂白后荧光恢复（FRAP）实验中分析了颗粒上的Rab动力学。EGFP-Rab 27 A的恢复曲线与ppANF-EGFP的恢复曲线相当，而EGFP-Rab 3A的恢复曲线明显更快，表明Rab 3A而不是Rab 27 A可能在颗粒和胞质溶胶之间快速交换。用10μM格尔德霉素抑制热休克蛋白90不影响交换过程或调节的胞吐作用。在活细胞中分析用300μM ATP刺激期间的Rab动力学。在刺激后，在细胞周围观察到颗粒状ppANF-EGFP荧光的损失，但仅观察到EGFP-Rab 3A和EGFP-Rab 27 A荧光的有限变化，表明Rab蛋白在刺激后不会立即解离或分散。这些数据表明Rab 3A和Rab 27 A可能具有不同的作用，我们认为，发现年轻的分泌颗粒具有较高的结合Rab 3A和Rab 27 A的能力可能是功能上重要的优先从这些颗粒胞吐。
We have assessed the dynamics of the association of Rab3A and Rab27A with secretory granules at various stages of their life in PC12 cells. Endogenous Rab3A colocalised with the secretory granule marker secretogranin II (SGII) and expressed EGFP-Rab3A and ECFP-Rab27A colocalised with one another. The extent of colocalisation between EGFP-Rab3A or EGFP-Rab27 and SGII increased after longer times post-transfection suggesting that these Rab proteins are preferentially recruited to newly synthesised granules. Following the release of immature secretory granules from the trans-Golgi network, Rab3A and Rab27A became associated with the immature granules after a lag period of around 20 minutes. Rab dynamics on granules were analysed in fluorescence recovery after photobleaching (FRAP) experiments. The recovery profile of EGFP-Rab27A was comparable to that of ppANF-EGFP, while the recovery profile of EGFP-Rab3A was significantly faster, indicating that Rab3A but not Rab27A may be rapidly exchanged between granules and cytosol. Inhibition of heat-shock protein 90 with 10μM geldanamycin did not affect the exchange process or regulated exocytosis. Rab dynamics during stimulation with 300μM ATP were analysed in live cells. Loss of granular ppANF-EGFP fluorescence was seen at the cell periphery after stimulation but only limited changes in EGFP-Rab3A and EGFP-Rab27A fluorescence was observed, indicating that the Rab proteins do not immediately dissociate or disperse on stimulation. The data suggest potentially distinct roles for Rab3A and Rab27A and we suggest that the finding that young secretory granules have a higher capacity for binding Rab3A and Rab27A may be functionally important for preferential exocytosis from these granules.
登录
查看更多内容
Rab27a及其效应子myrip将分泌颗粒与F-肌动蛋白联系起来，并控制其向释放位点的运动。
影响因子：
7.8
作者：
Desnos, Claire;Schonn, Jean-Sebastien;Huet, Sebastien;Tran, Viet Samuel;El-Amraoui, Aziz;Raposo, Graca;Fanget, Isabelle;Chapuis, Catherine;Menasche, Gael;de Saint Basile, Genevieve;Petit, Christine;Cribier, Sophie;Henry, Jean-Pierre;Darchen, Francois
通讯作者：
Darchen, Francois
影响因子：
4.8
作者：
Haynes, LP;Thomas, GMH;Burgoyne, RD
通讯作者：
Burgoyne, RD
影响因子：
3.9
作者：
Graham, ME;Fisher, RJ;Burgoyne, RD
通讯作者：
Burgoyne, RD
影响因子：
7.8
作者：
Haddad, EK;Wu, XF;Henkart, PA
通讯作者：
Henkart, PA
影响因子：
3.3
作者：
Ganley, IG;Carroll, K;Pfeffer, S
通讯作者：
Pfeffer, S