Interactions of actin, myosin, and a new actin-binding protein of rabbit pulmonary macrophages. II. Role in cytoplasmic movement and phagocytosis.
Interactions of actin, myosin, and a new actin-binding protein of rabbit pulmonary macrophages. II. Role in cytoplasmic movement and phagocytosis.
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DOI：
10.1083/jcb.68.3.602
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发表时间：
1976-03
期刊：
影响因子：
--
通讯作者：
Hartwig JH
中科院分区：
文献类型：
--
作者：
Stossel TP;Hartwig JH
兔肺巨噬细胞的肌动蛋白和肌球蛋白受另外两种蛋白质的影响。巨噬细胞肌球蛋白Mg 2 ATP酶活性的肌动蛋白活化需要蛋白辅因子，并且高分子量肌动蛋白结合蛋白聚集肌动蛋白丝（Stossel T. P.，和J.H.哈特维希1975. J.Biol.Chem.250：5706-5711）9当在含有Mg 2-ATP和二硫苏糖醇的0.34M蔗糖溶液中加热时，这四种蛋白质协同相互作用。acin结合蛋白在肌动蛋白存在下导致肌动蛋白形成凝胶，当冷却时液化。肌球蛋白将凝胶收缩成聚集体，辅因子加速了聚集的速度。因此，我们认为这四种蛋白质也影响含Mg ~（2-）-ATP和二硫苏糖醇的粗蔗糖提取物肺巨噬细胞的温度依赖性凝胶和聚集。凝胶提取物由缠结的细丝组成。相对于静止巨噬细胞的匀浆，肌动蛋白结合蛋白在吞噬巨噬细胞的匀浆中的分布被改变，使得2-6倍的肌动蛋白结合蛋白是可溶的。吞噬巨噬细胞的蔗糖提取物比静止巨噬细胞的提取物更快地凝胶化。肺巨噬细胞的吞噬作用涉及含有细丝的外周伪足的形成。研究结果表明，肌动蛋白结合蛋白启动了一个合作的相互作用的收缩蛋白质产生细胞质凝胶化，吞噬作用影响的肌动蛋白结合蛋白的行为。
Actin and myosin of rabbit pulmonary macrophages are influenced by two other proteins. A protein cofactor is required for the actin activation of macrophage myosin Mg2 ATPase activity, and a high molecular weight actin-binding protein aggregates actin filaments (Stossel T.P., and J.H. Hartwig. 1975. J. Biol. Chem. 250:5706-5711)9 When warmed in 0.34 M sucrose solution containing Mg2-ATP and dithiothreitol, these four proteins interact cooperatively. Acin-binding protein in the presence of actin causes the actin to form a gel, which liquifies when cooled. The myosin contracts the gel into an aggregate, and the rate of aggregation is accelerated by the cofactor. Therefore, we believe that these four proteins also effec the temperature-dependent gelation and aggregation of crude sucrose extracts pulmonary macrophages containing Mg2-ATP and dithiothreitol. The gelled extracts are composed of tangled filaments. Relative to homogenates of resting macrophages, the distribution of actin-binding protein in homogenates of phagocytizing macrophages is altered such that 2-6 times more actin-binding protein is soluble. Sucrose extracts of phagocytizing macrophages gel more rapidly than extracts of resting macrophages. Phagocytosis by pulmonary macrophages involves the formation of peripheral pseudopods containing filaments. The findings suggest that the actin-binding protein initiates a cooperative interaction of contractile proteins to generate cytoplasmic gelation, and that phagocytosis influences the behavior of the actin-binding protein.