Department of Physiology, Semmelweis University, Budapest, Hungary.
Eur J Clin Invest. 2018 Nov;48 Suppl 2:e12993. doi: 10.1111/eci.12993. Epub 2018 Aug 7.
GTPase-activating proteins (GAPs) accelerate the rate of hydrolysis of GTP bound to small GTPases, thereby limiting the prevalence and concentration of the active, GTP-bound form of these proteins. The large number of potential GAPs acting on members of the Rho family of small GTPases raises the question of specificity or redundancy.
In this review, we summarize experimental data obtained on the role of Rho family GAPs in neutrophils, highlight cases where more than one GAP is involved in a physiological function and show examples that GAPs can be involved not only in termination but also in initiation of cellular processes. We demonstrate that the expression-level regulation of GAPs may also occur in short-living cells such as neutrophils. Finally, we provide insight into the existence and structure of molecular complexes in which Rho family GAPs are involved.
GAPs play more complex and varied roles than being simple terminators of cellular processes.
GTP 酶激活蛋白（GAPs）可加速与小 GTP 酶结合的 GTP 的水解速率，从而限制这些蛋白的活性、GTP 结合形式的普遍性和浓度。大量可能的 GAP 作用于 Rho 家族的小 GTP 酶，引发了特异性或冗余性的问题。
在这篇综述中，我们总结了关于 Rho 家族 GAP 在中性粒细胞中的作用的实验数据，强调了在生理功能中涉及不止一种 GAP 的情况，并展示了 GAP 不仅可以参与细胞过程的终止，还可以参与细胞过程的起始的例子。我们证明，GAP 的表达水平调节也可能发生在中性粒细胞等寿命较短的细胞中。最后，我们深入了解 Rho 家族 GAP 参与的分子复合物的存在和结构。
GAP 发挥的作用比简单地终止细胞过程更为复杂和多样化。
