Dharmawardhane S, Warren V, Hall A L, Condeelis J
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461.
Cell Motil Cytoskeleton. 1989;13(1):57-63. doi: 10.1002/cm.970130107.
Triton-insoluble cytoskeletons were isolated from Dictyostelium discoideum AX3 cells prior to and following stimulation with 2'deoxy cyclic adenosine monophosphate (cAMP). Temporal changes in the content of actin and a 120,000 dalton actin-binding protein (ABP-120) in cytoskeletons following stimulation were monitored. Both actin and ABP-120 were incorporated into the cytoskeleton at 30-40 seconds following stimulation, which is cotemporal with the onset of pseudopod extension during stimulation of amoebae with chemoattractants. Changes in the content of total cytoskeletal protein and cytoskeletal myosin were determined under the same experimental conditions as controls. These proteins exhibited different kinetics from those of cytoskeletal ABP-120 and actin following the addition of 2'deoxy cAMP. The authors concluded that the association of ABP-120 with the cytoskeleton is regulated during cAMP signalling. Furthermore, these results indicate that ABP-120 is involved in cross-linking newly assembled actin filaments into the cytoskeleton during chemoattractant-stimulated pseudopod extension.
在用2'-脱氧环磷酸腺苷（cAMP）刺激之前和之后，从盘基网柄菌AX3细胞中分离出不溶于Triton的细胞骨架。监测刺激后细胞骨架中肌动蛋白和一种120,000道尔顿肌动蛋白结合蛋白（ABP-120）含量的时间变化。刺激后30-40秒时，肌动蛋白和ABP-120都被整合到细胞骨架中，这与用趋化剂刺激变形虫时伪足延伸的开始是同时发生的。在与对照相同的实验条件下测定总细胞骨架蛋白和细胞骨架肌球蛋白的含量变化。加入2'-脱氧cAMP后，这些蛋白质表现出与细胞骨架ABP-120和肌动蛋白不同的动力学。作者得出结论，在cAMP信号传导过程中，ABP-120与细胞骨架的结合受到调控。此外，这些结果表明，在趋化剂刺激的伪足延伸过程中，ABP-120参与将新组装的肌动蛋白丝交联到细胞骨架中。
