Kinesin-1 (uKHC/KIF5B) is Required for Bidirectional Motility of ER Exit Sites and Efficient ER-to-Golgi Transport
Kinesin-1 (uKHC/KIF5B) is Required for Bidirectional Motility of ER Exit Sites and Efficient ER-to-Golgi Transport
复制标题
DOI：
10.1111/j.1600-0854.2008.00811.x
复制
发表时间：
2008-11-01
期刊：
影响因子：
4.5
通讯作者：
Stephens, David J.
中科院分区：
文献类型：
--
作者：
Gupta, Vijay;Palmer, Krysten J.;Stephens, David J.
蛋白质和脂质在细胞内区室之间的转运是真核细胞的组织和功能的基础。通过将膜偶联到微管，该过程的效率大大提高。这有两个功能，细胞器定位和囊泡运输。在这项研究中，我们表明，除了众所周知的负端运动动力蛋白在内质网（ER）到高尔基体运输的作用，正端定向运动驱动蛋白-1参与定位外壳蛋白II包被的ER出口位点（ERES）在细胞中，以及运输载体的形成和它们的运动到高尔基体。使用二维高斯拟合，以确定它们的位置在高空间分辨率，我们表明，ERES进行短程双向运动。双向性依赖于驱动蛋白-1和动力蛋白。抑制驱动蛋白-1（KIF 5 B）也抑制ER-高尔基体转运并影响ER-高尔基体转运载体的形态。此外，我们发现，抑制动力蛋白重链的表达增加了ERES的运动范围，这表明动力蛋白可能锚ERES，或ER本身，微管。这些数据暗示驱动蛋白-1在ER/高尔基体界面的空间组织以及在ER外的交通。
Transport of proteins and lipids between intracellular compartments is fundamental to the organization and function of eukaryotic cells. The efficiency of this process is greatly enhanced through coupling of membranes to microtubules. This serves two functions, organelle positioning and vesicular transport. In this study, we show that in addition to the well-known role for the minus-end motor dynein in endoplasmic reticulum (ER)-to-Golgi transport, the plus-end-directed motor kinesin-1 is involved in positioning coat protein II-coated ER exit sites (ERES) in cells as well as the formation of transport carriers and their movement to the Golgi. Using two-dimensional Gaussian fitting to determine their location at high spatial resolution, we show that ERES undergo short-range bidirectional movements. Bidirectionality depends on both kinesin-1 and dynein. Suppression of kinesin-1 (KIF5B) also inhibits ER-to-Golgi transport and affects the morphology of ER-to-Golgi transport carriers. Furthermore, we show that suppression of dynein heavy chain expression increases the range of movement of ERES, suggesting that dynein might anchor ERES, or the ER itself, to microtubules. These data implicate kinesin-1 in the spatial organization of the ER/Golgi interface as well as in traffic outside the ER.