Association of profilin with filament-free regions of human leukocyte and platelet membranes and reversible membrane binding during platelet activation.
Association of profilin with filament-free regions of human leukocyte and platelet membranes and reversible membrane binding during platelet activation.
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DOI：
10.1083/jcb.109.4.1571
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发表时间：
1989-10
期刊：
影响因子：
--
通讯作者：
Kwiatkowski DJ
中科院分区：
文献类型：
--
作者：
Hartwig JH;Chambers KA;Hopcia KL;Kwiatkowski DJ
Profilin是一种广泛存在于真核细胞中的肌动蛋白单体结合蛋白。哺乳动物profilin可逆地螯合肌动蛋白单体在高亲和力profilactin复合物。在体外，该复合物响应于用聚磷酸肌醇、磷脂酰肌醇单磷酸和磷脂酰肌醇4，5-二磷酸处理而解离。在这里，我们证明了人白细胞和血小板中的profilin的超微结构免疫定位。在这两种细胞类型中，发现profilin的显著部分与缺乏肌动蛋白丝和其他可辨别结构的细胞膜区域相关。血小板活化后，profilin的膜结合可逆地增加。这项研究代表了第一个直接证据profilin和磷脂在体内的相互作用。
Profilin is a conserved, widely distributed actin monomer binding protein found in eukaryotic cells. Mammalian profilin reversibly sequesters actin monomers in a high affinity profilactin complex. In vitro, the complex is dissociated in response to treatment with the polyphosphoinositides, phosphatidylinositol monophosphate, and phosphatidylinositol 4,5-bisphosphate. Here, we demonstrate the ultrastructural immunolocalization of profilin in human leukocytes and platelets. In both cell types, a significant fraction of profilin is found associated with regions of cell membrane devoid of actin filaments and other discernible structures. After platelet activation, the membrane association of profilin reversibly increases. This study represents the first direct evidence for an interaction between profilin and phospholipids in vivo.