期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1979
卷号：76
期号：8
页码：3814-3818
DOI：10.1073/pnas.76.8.3814
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Graessmann's microinjection technique was chosen to introduce fluorescently labeled muscle actin and other proteins into WI-38 human fibroblasts. The injected cells were examined during culture by fluorescence and reflection contrast microscopy. Within 30 min after injection, rhodamine-labeled actin was incorporated into a distinct network of fluorescent filaments, resembling the stress fibers observed by classical immunofluorescence microscopy. Cytochalasin b prevented the formation of these fibers, but colchicine did not. Neighboring fibers often converged into distinct focal points that appeared to be concentrated near the base of the cell. Examination of these fluorescent fibers and focal points by reflection contrast microscopy confirmed their close location to the substratum. After 6 hr of culture, fluorescent actin and the control proteins were segregated into granules located mainly near the cell nucleus. Thus, the injected actin both enters the intrinsic actin pool and participates in an assembly and disassembly of filamentous structures. Segregation into granules traces the natural turnover of this protein within the cell.
