Studies on regulation of transport vesicle budding from endoplasmic reticulum by the calcium-binding protein ALG-2

Sec31A是内质网（ER）到高尔基转运囊泡的COPII外壳的外部成分。我们之前发现五ef -hand蛋白ALG-2钙依赖性与Sec31A相互作用。在这项研究中，我们首先将负责ALG-2结合的Sec31A区域缩小到13个氨基酸。接下来，光破坏分析后的荧光恢复显示，ag -2结合区构成了Sec31A对ER膜的高亲和力结合位点。最后，钙/磷脂结合蛋白annexin All通过ALG-2的接头功能被鉴定为COPII出芽位点的招募蛋白。

Sec31A is an outer component of COPII coat of endoplasmic reticulum (ER)-to-Golgi transport vesicles. We previously found that the penta-EF-hand protein ALG-2 calcium-dependently interacts with Sec31A. In this study, we first narrowed the Sec31A region responsible for ALG-2 binding to 13 amino acids. Next, fluorescence recovery after photobreaching analysis revealed that the ALG-2 binding region constitutes a high affinity binding site of Sec31A for the ER membrane. Finally, the calcium/phospholipid binding protein annexin All was identified as a recruiting protein to the budding site of COPII by the adaptor function of ALG-2.