Organelle size control - increasing vacuole content activates SNAREs to augment organelle volume through homotypic fusion
Organelle size control - increasing vacuole content activates SNAREs to augment organelle volume through homotypic fusion
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DOI：
10.1242/jcs.184382
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发表时间：
2016-07-15
影响因子：
4
通讯作者：
Mayer, Andreas
中科院分区：
文献类型：
--
作者：
Desfougeres, Yann;Neumann, Heinz;Mayer, Andreas
细胞控制相对于细胞体积的区室大小，但每个细胞器内部也有大小控制。酵母液泡既不会破裂，也不会塌陷成皱褶状，这表明细胞器包膜的体积与内容物的数量相适应。人们很难理解这种调整是如何实现的。我们发现，酵母液泡中积累的内容激活了其他液泡的融合，从而增加了体积与表面的比。储存在液泡内的优势化合物聚磷酸盐的合成刺激伴侣蛋白Sec18/NSF与液泡SNAREs结合，从而激活它们并触发融合。SNAREs只能被管状多磷酸激活，而不能被细胞质多磷酸激活。胞浆中细胞周期蛋白依赖激酶Pho80-Pho85和R-SNARE Nyv1对管腔息肉的控制。这些结果表明，细胞可以通过从液泡腔到细胞器细胞质表面的SNAREs的反馈来适应液泡的体积。
Cells control the size of their compartments relative to cell volume, but there is also size control within each organelle. Yeast vacuoles neither burst nor do they collapse into a ruffled morphology, indicating that the volume of the organellar envelope is adjusted to the amount of content. It is poorly understood how this adjustment is achieved. We show that the accumulating content of yeast vacuoles activates fusion of other vacuoles, thus increasing the volume-to-surface ratio. Synthesis of the dominant compound stored inside vacuoles, polyphosphate, stimulates binding of the chaperone Sec18/NSF to vacuolar SNAREs, which activates them and triggers fusion. SNAREs can only be activated by lumenal, not cytosolic, polyphosphate (polyP). Control of lumenal polyP over SNARE activation in the cytosol requires the cytosolic cyclin-dependent kinase Pho80-Pho85 and the R-SNARE Nyv1. These results suggest that cells can adapt the volume of vacuoles to their content through feedback from the vacuole lumen to the SNAREs on the cytosolic surface of the organelle.