Influence of organelle geometry on the apparent binding kinetics of peripheral membrane proteins.
Influence of organelle geometry on the apparent binding kinetics of peripheral membrane proteins.
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细胞器几何形状对外周膜蛋白表观结合动力学的影响
DOI：
10.1103/physreve.91.022721
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
M. Weiss
中科院分区：
文献类型：
--
作者：
J. Hoffmann;R. Fickentscher ;M. Weiss
活细胞中的信息处理经常涉及细胞质和细胞器膜之间的外周膜蛋白的交换。这些缔合-解离循环的典型时间尺度通常通过光漂白后的荧光恢复（FRAP）在体内进行量化。与常见假设相反，我们在此表明 FRAP 确定的值取决于目标结构的大小和数量。因此，仅凭 FRAP 时间不足以得出有关蛋白质结合动力学的结论。相比之下，从 FRAP 方法中提取主要分子缔合和解离速率为蛋白质的结合动力学提供了一种与尺寸无关的、因此可靠的测量方法。我们通过对与高尔基体膜短暂结合的小 GTPase Arf-1 进行的实验来支持我们的理论考虑：虽然未经处理的细胞和微管破坏的细胞中 Arf-1 的恢复时间显着不同，但两种情况下的分子动力学速率相同。
Information processing in living cells frequently involves an exchange of peripheral membrane proteins between the cytosol and organelle membranes. The typical time scaleof these association-dissociation cycles is commonly quantifiedin vivovia fluorescence recovery after photobleaching (FRAP). Contrary to common assumptions, we show here thatvalues determined by FRAP depend on the size and number of target structures. Hence, FRAP times alone are insufficient to draw conclusions about the proteins' binding kinetics. In contrast, extracting primary molecular association and dissociation rates from FRAP approaches provides a size-independent and therefore robust measure for the proteins' binding kinetics. We support our theoretical considerations with experiments on the small GTPase Arf-1 that transiently associates with Golgi membranes: While Arf-1 recovery times in untreated cells and in cells with disrupted microtubules are significantly different, the molecular kinetic rates are shown to be the same in both cases.