DYNAMIC ASPECTS OF FILOPODIAL FORMATION BY REORGANIZATION OF MICROFILAMENTS
DYNAMIC ASPECTS OF FILOPODIAL FORMATION BY REORGANIZATION OF MICROFILAMENTS
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DOI：
10.1083/jcb.73.2.479
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发表时间：
1977-01-01
影响因子：
7.8
通讯作者：
EDDS, KT
中科院分区：
文献类型：
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作者：
EDDS, KT
用50 mM乙二醇双(β-氨基乙基)-N，N，N‘’，N‘’-四乙酸酯，50 mM Tris-HCl，pH 7.8，可防止海胆的体细胞凝集，然后在蔗糖梯度上分离成不同类型的细胞。一种细胞类型，花瓣状的体腔细胞，自发地经历了惊人的形态转变，形成了一种具有大量细小的细胞质突起(丝状足细胞)的形式。这种转变是可逆的。在超微结构上，丝状足基的形成是含有肌动蛋白的细丝逐渐重组成径向取向的束的结果。丝状束的形成始于细胞的S周缘，向内进行。同时，束之间的细胞质被抽出，露出指状的丝状柄。最终，丝状柄可以延长到原始长度的4倍。从生物化学上讲，肌动蛋白是整个细胞匀浆中含量最丰富的蛋白质，可以通过丙酮粉提取毫克量。还可以从这些细胞中分离出肌球蛋白复合体，推测它在产生所观察到的各种形式的运动方面具有活性。
Coelomocytes of the sea urchin Strongylocentrotus droebachiensis, may be prevented from clotting with 50 mM ethylene glycol-bis(.beta.-aminoethyl)-N,N,N'',N''-tetraacetate, 50 mM Tris-HCl, pH 7.8 and subsequently separated into various cell types on sucrose gradients. One cell type, the petaloid coelomocyte, spontaneously undergoes a striking morphological transformation to a form exhibiting numerous, thin cytoplasmic projections (filopodia). The transformation is reversible. Ultrastructurally, the formation of the filopodia results from a progressive reorganization of actin-containing filaments into radially oriented bundles. The formation of the filament bundles is initiated at the cell''s periphery and proceeds inward. Simultaneously, the cytoplasm in between the bundles is withdrawn, exposing finger-like filopodia. Ultimately, the filopodia can be extended by up to 4 times their original length. Biochemically, actin is the most abundant protein in whole cell homogenates and is extractable in milligram quantities via acetone powders. An actomyosin complex may also be isolated from these cells and is presumed to be active in producing the various forms of motility observed.