Jaiswal Jyoti K, Andrews Norma W, Simon Sanford M
Laboratory of Cellular Biophysics, Rockefeller University, New York, NY 10021, USA.
J Cell Biol. 2002 Nov 25;159(4):625-35. doi: 10.1083/jcb.200208154. Epub 2002 Nov 18.
Similar to its role in secretory cells, calcium triggers exocytosis in nonsecretory cells. This calcium-dependent exocytosis is essential for repair of membrane ruptures. Using total internal reflection fluorescence microscopy, we observed that many organelles implicated in this process, including ER, post-Golgi vesicles, late endosomes, early endosomes, and lysosomes, were within 100 nm of the plasma membrane (in the evanescent field). However, an increase in cytosolic calcium led to exocytosis of only the lysosomes. The lysosomes that fused were predominantly predocked at the plasma membrane, indicating that calcium is primarily responsible for fusion and not recruitment of lysosomes to the cell surface.
与它在分泌细胞中的作用类似，钙在非分泌细胞中触发胞吐作用。这种钙依赖性胞吐作用对于膜破裂的修复至关重要。利用全内反射荧光显微镜，我们观察到参与这一过程的许多细胞器，包括内质网、高尔基体后囊泡、晚期内体、早期内体和溶酶体，都位于质膜100纳米范围内（在倏逝场中）。然而，胞质钙的增加仅导致溶酶体的胞吐作用。融合的溶酶体主要预先停靠在质膜上，这表明钙主要负责融合，而不是将溶酶体招募到细胞表面。
