Cofilin nuclear-cytoplasmic shuttling affects cofilin-actin rod formation during stress
Cofilin nuclear-cytoplasmic shuttling affects cofilin-actin rod formation during stress
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DOI：
10.1242/jcs.097667
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发表时间：
2012-09-01
影响因子：
4
通讯作者：
Truant, Ray
中科院分区：
文献类型：
--
作者：
Munsie, Lise Nicole;Desmond, Carly R.;Truant, Ray
在典型的稳态条件下，以及在细胞应激条件下，Cofilin蛋白参与调节肌动蛋白细胞骨架，其中Cofilin使F-肌动蛋白饱和，形成Cofilin-actin棒。Cofilin可以通过主动核定位信号（NLS）进入细胞核，在应激期间积累在核肌动蛋白杆中。在这里，我们的特点是积极的核输出的cofilin通过一个链霉素B敏感，CRM 1依赖，核输出信号（内斯）。我们还重新定义的NLS的cofilin作为一个二分NLS，与核定位所需的额外的基本表位。使用荧光寿命成像显微镜（FLIM）和福斯特共振能量转移（FRET）之间的cofilin部分和肌动蛋白，以及在活细胞中的自动化图像分析，我们已经定义了微妙的突变cofilin NLS，使cofilin结合肌动蛋白在体内和影响cofilin动态应力。我们进一步定义的要求cofilin-actin杆形成在一个系统中的细胞应激的时间活细胞成像。我们提出，cofilin核穿梭是关键的cofilin-actin杆应力响应与cofilin动态细胞核和细胞质之间的通信过程中的细胞应力。
Cofilin protein is involved in regulating the actin cytoskeleton during typical steady state conditions, as well as during cell stress conditions where cofilin saturates F-actin, forming cofilin-actin rods. Cofilin can enter the nucleus through an active nuclear localization signal (NLS), accumulating in nuclear actin rods during stress. Here, we characterize the active nuclear export of cofilin through a leptomycin-B-sensitive, CRM1-dependent, nuclear export signal (NES). We also redefine the NLS of cofilin as a bipartite NLS, with an additional basic epitope required for nuclear localization. Using fluorescence lifetime imaging microscopy (FLIM) and Forster resonant energy transfer (FRET) between cofilin moieties and actin, as well as automated image analysis in live cells, we have defined subtle mutations in the cofilin NLS that allow cofilin to bind actin in vivo and affect cofilin dynamics during stress. We further define the requirement of cofilin-actin rod formation in a system of cell stress by temporal live-cell imaging. We propose that cofilin nuclear shuttling is critical for the cofilin-actin rod stress response with cofilin dynamically communicating between the nucleus and cytoplasm during cell stress.