Dynein motor regulation stabilizes interphase microtubule arrays and determines centrosome position
Dynein motor regulation stabilizes interphase microtubule arrays and determines centrosome position
复制标题
DOI：
10.1093/emboj/18.23.6786
复制
发表时间：
1999-12-01
期刊：
影响因子：
11.4
通讯作者：
Gerisch, G
中科院分区：
文献类型：
--
作者：
Koonce, MP;Köhler, J;Gerisch, G
细胞质动力蛋白是一种以微管为基础的运动蛋白，负责真核细胞中囊泡的运动和纺锤体的定位。我们在这里表明，动力蛋白也支持微管结构，并决定了间期细胞的中心体位置。Dictyostelius中运动域的过度表达导致间期微管阵列的崩溃，形成通常包裹细胞核的松散的束状结构。使用绿色荧光蛋白(GFP)-α-微管蛋白来显示活细胞中的微管，我们发现坍塌的阵列仍然与中心体相关，并且具有高度的运动性，通常沿着细胞皮质的内表面循环。这与野生型细胞截然不同，在野生型细胞中，中心体的移动受到微管阵列上的张力平衡的限制。中心体运动涉及皮层上产生力量的微管相互作用，其速度和方向与动力蛋白介导的机制一致。将过度表达效应映射到重链的C-末端区域突出了大量序列中对调节运动活动重要的功能结构域。
Cytoplasmic dynein is a microtubule-based motor protein responsible for vesicle movement and spindle orientation in eukaryotic cells. We show here that dynein also supports microtubule architecture and determines centrosome position in interphase cells. Overexpression of the motor domain in Dictyostelium leads to a collapse of the interphase microtubule array, forming loose bundles that often enwrap the nucleus. Using green fluorescent protein (GFP)-alpha-tubulin to visualize microtubules in live cells, we show that the collapsed arrays remain associated with centrosomes and are highly motile, often circulating along the inner surface of the cell cortex. This is strikingly different from wild-type cells where centrosome movement is constrained by a balance of tension on the microtubule array. Centrosome motility involves force-generating microtubule interactions at the cortex, with the rate and direction consistent with a dynein-mediated mechanism. Mapping the overexpression effect to a C-terminal region of the heavy chain highlights a functional domain within the massive sequence important for regulating motor activity.