Murti K G, Smith H T, Fried V A
Department of Biochemistry, St. Jude Children's Research Hospital, Memphis, TN 38101.
Proc Natl Acad Sci U S A. 1988 May;85(9):3019-23. doi: 10.1073/pnas.85.9.3019.
Immunofluorescence microscopy was used to study the intracellular localization of ubiquitin. Baby hamster kidney cells (BHK cells) and several other cell lines were probed with a well characterized monoclonal antibody to ubiquitin. The antibody stained a complex cellular structure that we identified as the microtubule network. The anti-ubiquitin antibody bound to the microtubule network at all stages of the cell cycle, and we showed that the apparent association of ubiquitin with the microtubule network is not an artifact of crosslinking of free ubiquitin to the cell structure. Immunoblot procedures demonstrated that tubulin itself was not ubiquitinated. We propose that ubiquitin and/or ubiquitin-protein conjugates are associated with those networks as a new class of microtubule-associated protein. The targeting of ubiquitin to specific sites within the cell by its association with the microtubule network may regulate some of the functions of ubiquitin.
免疫荧光显微镜术被用于研究泛素的细胞内定位。用一种特性明确的抗泛素单克隆抗体检测了幼仓鼠肾细胞（BHK细胞）及其他几种细胞系。该抗体染色了一种复杂的细胞结构，我们将其鉴定为微管网络。抗泛素抗体在细胞周期的所有阶段均与微管网络结合，并且我们表明泛素与微管网络的明显关联并非游离泛素与细胞结构交联的人为产物。免疫印迹程序表明微管蛋白本身并未被泛素化。我们提出泛素和/或泛素 - 蛋白质缀合物作为一类新的微管相关蛋白与那些网络相关联。泛素通过与微管网络结合而靶向细胞内的特定部位可能会调节泛素的某些功能。
