Risco C, Menéndez-Arias L, Copeland T D, Pinto da Silva P, Oroszlan S
Biological Carcinogenesis and Development Program, Program Resources, Inc./Dyncorp, Frederick, MD, USA.
J Cell Sci. 1995 Sep;108 ( Pt 9):3039-50. doi: 10.1242/jcs.108.9.3039.
The entry and intracellular transport of Moloney-murine leukemia virions inside mouse NIH 3T3 cells have been followed by electron microscopy techniques. Five viral proteins--matrix (MA, p15), capsid (CA, p30), nucleocapsid (NC, p10), integrase (IN), and the envelope glycoprotein (SU, gp70)--were located by immunolabeling using gold probes. After entering the cells, viral particles were frequently detected inside cytoplasmic vesicles of variable size. Their viral envelope was apparently lost during intracytoplasmic transport. When the unenveloped viral cores reached the nuclear membrane or its vicinity, they were disrupted. Two of the immunolabeled proteins, NC and IN, were detected entering the nucleus of non-dividing cells, where both were targeted to the nucleolus. However, MA and CA were found only in the cytoplasm. NC is a nucleic acid-binding protein which contains potential nuclear localization signals. We suggest that NC could enter the nucleus as part of a nucleoprotein complex, associated with IN, and possibly, also with viral DNA.
利用电子显微镜技术追踪了莫洛尼氏小鼠白血病病毒粒子在小鼠NIH 3T3细胞内的进入及细胞内运输过程。通过使用金探针进行免疫标记定位了五种病毒蛋白——基质（MA，p15）、衣壳（CA，p30）、核衣壳（NC，p10）、整合酶（IN）和包膜糖蛋白（SU，gp70）。进入细胞后，经常在大小不一的细胞质囊泡内检测到病毒粒子。其病毒包膜在胞质运输过程中明显丢失。当无包膜的病毒核心到达核膜或其附近时，它们会被破坏。检测到两种免疫标记蛋白NC和IN进入非分裂细胞的细胞核，二者均靶向核仁。然而，MA和CA仅存在于细胞质中。NC是一种核酸结合蛋白，含有潜在的核定位信号。我们认为NC可能作为核蛋白复合物的一部分进入细胞核，该复合物与IN相关，也可能与病毒DNA相关。
