Functionally distinct pools of actin in secretory cells
Functionally distinct pools of actin in secretory cells
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DOI：
10.1152/ajpcell.2001.281.2.c407
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发表时间：
2001-08-01
影响因子：
5.5
通讯作者：
Forte, JG
中科院分区：
文献类型：
--
作者：
Ammar, DA;Nguyen, PNB;Forte, JG
胃壁细胞的酸分泌是通过含有质子泵H+-K+-ATP酶（HK）的囊泡的运动来控制的。我们已经使用了latrunculin B（Lat B），它结合单体肌动蛋白，研究肌动蛋白营业额在受刺激的壁细胞。在离体胃腺中，需要相对高浓度的LatB B来抑制酸积累（ED 50类似于70 μ M）。培养的壁细胞在低Lat B（0.1-1 μ M）的存在下刺激减少了板状伪足的形成和一些异常的点状鬼笔环肽染色的结构，但易位的HK和空泡肿胀似乎不受影响。高水平的Lat B（10-50 μ M）导致肌动蛋白组织的总体变化（遍布细胞和细胞核的点状鬼笔环肽染色结构），并减少HK的移位和空泡肿胀。高B处理的静息壁细胞对形态学和F-肌动蛋白染色的影响较小。如果用高Lat B处理的静息细胞在刺激前立即洗涤，则它们表现出正常的刺激形态。这些数据表明不同池壁细胞肌动蛋白：池高度敏感的拉特B主要参与运动功能的培养细胞;和拉特B-耐池，最有可能的微绒毛丝，这是必不可少的分泌。此外，刺激过程似乎加重了Lat B的作用，最有可能是通过Lat B结合到由运动肌动蛋白丝库的周转释放的单体肌动蛋白。
Acid secretion by the gastric parietal cell is controlled through movement of vesicles containing the proton pump, the H+-K+-ATPase (HK). We have used latrunculin B (Lat B), which binds to monomeric actin, to investigate actin turnover in the stimulated parietal cell. In isolated gastric glands, relatively high concentrations of Lat B were required to inhibit acid accumulation (ED50 similar to 70 muM). Cultured parietal cells stimulated in the presence of low Lat B (0.1-1 muM) have reduced lamellipodia formation and some aberrant punctate phalloidin-stained structures, but translocation of HK and vacuolar swelling appeared unaffected. High Lat B (10-50 muM) resulted in gross changes in actin organization (punctate phalloidin-stained structures throughout the cell and nucleus) and reduced translocation of HK and vacuolar swelling. Resting parietal cells treated with high Lat B showed minor effects on morphology and F-actin staining. If resting cells treated with high Lat B were washed immediately before stimulation, they exhibited a normal stimulated morphology. These data suggest distinct pools of parietal cell actin: a pool highly susceptible to Lat B primarily involved in motile function of cultured cells; and a Lat B-resistant pool, most likely microvillar filaments, that is essential for secretion. Furthermore, the stimulation process appears to accentuate the effects of Lat B, most likely through Lat B binding to monomer actin liberated by the turnover of the motile actin filament pool.