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：1978
卷号：75
期号：2
页码：857-861
DOI：10.1073/pnas.75.2.857
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Actin labeled with 5-iodoacetamidofluorescein has been incorporated into the functional pool of actin in Chaos carolinensis and Physarum polycephalum by direct microinjection. The functional activity of the labeled actin has been analyzed at three levels of organization as: (a) with the purified actin, (b) in motile extracts of cells, and (c) in living motile cells. The labeled actin exhibited normal polymerization and activated myosin ATPase to a similar extent as unlabeled controls. Labeled actin and endogenous actin were incorporated into contracted pellets to approximately the same extent in motile cell extracts. After labeled actin had been microinjected into single C. carolinensis cells, the fluorescent actin spread into both the endoplasm and etoplasm without forming distinct fibrils. In contrast, fluorescent bundles developed in the ectoplasm of P. polycephalum following microinjection of labeled actin. This experimental method in conjunction with fluorescence spectroscopic techniques could become a powerful tool for studying the intracellular distribution and structural changes of components in living cells.
