Drebrin particles:: components in the ensemble of proteins regulating actin dynamics of lamellipodia and filopodia
Drebrin particles:: components in the ensemble of proteins regulating actin dynamics of lamellipodia and filopodia
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DOI：
10.1078/0171-9335-00194
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发表时间：
2001-09-01
影响因子：
6.6
通讯作者：
Franke, WW
中科院分区：
文献类型：
--
作者：
Peitsch, WK;Hofmann, I;Franke, WW
Drebrin 是一种肌动蛋白结合 70 kDa 蛋白，具有异常缓慢的 SDS-PAGE 迁移率，相当于 120 kDa，含有富含脯氨酸的 profilin 结合基序，最初是在神经元细胞中报道的，但最近也在多种其他类型的组织和细胞系中发现。在各种细胞和组织的生化分析中，采用凝胶过滤、蔗糖梯度离心、免疫沉淀和印迹，我们已经鉴定出可溶性drebrin的不同状态：类似于4S单体、8S、约。 217-kDa 推定三聚体、13S 和 > 20S 寡聚体。在 8S 颗粒中，仅检测到化学计量的 [S-35] 甲硫氨酸标记的 Drebrin，但没有检测到其他肌动蛋白结合蛋白。通过免疫荧光和免疫电子显微镜，drebrin阳性物质通常以直径达400微米的“颗粒”形式出现，在一些细胞类型中聚集在高尔基体附近或板状伪足中，特别是在前缘，或在尖端（顶足）或前缘皱褶处的致密膜下团块中，在丝状伪足和 粘附连接处的斑块。我们得出的结论是，这些drebrin复合物和富含drebrin的结构允许在调节肌动蛋白丝组装的战略位置建立和维持高局部drebrin浓度，从而有助于细胞运动和形态，特别是可塑性的局部变化和突起的形成。
Drebrin, an actin-binding 70-kDa protein with an unusually slow SDS-PAGE mobility corresponding to similar to 120 kDa, containing a proline-rich, profilin-binding motif, had originally been reported from neuronal cells, but recently has also been found in diverse other kinds of tissues and cell lines. In biochemical analyses of various cells and tissues, employing gel filtration, sucrose gradient centrifugation, immunoprecipitation and -blotting, we have identified distinct states of soluble drebrin: a similar to 4S monomer, an 8S, ca. 217-kDa putative trimer, a 13S and a > 20S oligomer. In the 8S particles only [S-35]methionine-labelled drebrin but no other actin-binding protein has been detected in stoichiometric amounts. By immunofluorescence and immunoelectron microscopy, drebrin-positive material often appeared as "granules" up to 400 urn in diameter, in some cell types clustered near the Golgi apparatus or in lamellipodia, particularly at leading edges, or in dense-packed submembranous masses at tips (acropodia) or ruffles of leading edges, in filopodia and at plaques of adhering junctions. We conclude that these drebrin complexes and drebrin-rich structures allow the build-up and maintenance of high local drebrin concentrations in strategic positions for the regulation of actin filament assembly, thereby contributing to cell motility and morphology, in particular local changes of plasticity and the formation of protrusions.