Stendahl O I, Hartwig J H, Brotschi E A, Stossel T P
J Cell Biol. 1980 Feb;84(2):215-24. doi: 10.1083/jcb.84.2.215.
Actin-binding protein (ABP) and myosin are proteins that influence the rigidity and movement, respectively, of actin filaments in vitro. We examined the distribution of ABP and myosin molecules in acetone-fixed rabbit lung macrophages by means of immunofluorescence. The staining for both of these proteins in unspread cells was quite uniform, but was reduced in the nucleus and concentrated slightly in the periphery. The peripheral accumulation of staining attenuated in uniformly spread cells, although filopodia and hyaline veils definitely stained. In cells fixed during ingestion of yeast particles, the brightest staining correlated with the disposition of organelle-excluding pseudopodia initially surrounding the yeast. After phagocytosis was complete and the yeasts resided in intracellular vacuoles, no concentration of staining around the ingested yeasts was detectable. We conclude that ABP and myosin molecules are components of the structural unit of the cell responsible for spreading and phagocytosis, the hyaline cortex, a region known to be rich in actin filaments. The findings are consistent with the theory that these molecules control the rigidity and movement of filaments in the periphery of the living macrophage.
肌动蛋白结合蛋白（ABP）和肌球蛋白是分别在体外影响肌动蛋白丝的刚性和运动的蛋白质。我们通过免疫荧光检查了丙酮固定的兔肺巨噬细胞中ABP和肌球蛋白分子的分布。在未铺展的细胞中，这两种蛋白质的染色相当均匀，但在细胞核中减少，在周边略有集中。在均匀铺展的细胞中，染色的周边积累减弱，尽管丝状伪足和透明面纱明显染色。在吞噬酵母颗粒期间固定的细胞中，最亮的染色与最初围绕酵母的排除细胞器的伪足的分布相关。吞噬作用完成且酵母驻留在细胞内液泡中后，在摄入的酵母周围未检测到染色集中。我们得出结论，ABP和肌球蛋白分子是细胞结构单元的组成部分，负责铺展和吞噬作用，即透明皮质，这是一个已知富含肌动蛋白丝的区域。这些发现与这些分子控制活巨噬细胞周边细丝的刚性和运动的理论一致。
