Oligomerization, F-actin interaction, and membrane association of the ubiquitous mammalian coronin 3 are mediated by its carboxyl terminus
Oligomerization, F-actin interaction, and membrane association of the ubiquitous mammalian coronin 3 are mediated by its carboxyl terminus
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DOI：
10.1074/jbc.m205136200
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发表时间：
2002-12-13
影响因子：
4.8
通讯作者：
Hasse, A
中科院分区：
文献类型：
--
作者：
Spoerl, Z;Stumpf, M;Hasse, A
Coronin 3 是哺乳动物中普遍表达的 Coronin 蛋白家族成员。在成纤维细胞和 HEK 293 细胞中，它位于细胞质和膜下细胞骨架中，特别是在板状伪足和膜皱褶处。所有冠蛋白的羧基末端都包含一个卷曲的线圈，建议介导二聚化。我们在此表明，与其他 Coronin 同源物相比，重组人 Coronin 3 羧基末端形成寡聚体而不是二聚体，并且该部分足以在体外结合并交联 F-肌动蛋白。单独的羧基末端也可在体内赋予膜缔合性，去除卷曲线圈可消除膜定位，但在体外则不会消除 F-肌动蛋白结合。 Coronin 3 仅作为寡聚物从细胞质和膜部分中提取。由于其他 Coronin 没有报道寡聚化，因此它可能是控制 Coronin 3 特异性功能的关键特征。胞质 Coronin 3 显示出高度磷酸化，这可能调节该蛋白的亚细胞定位。
Coronin 3 is a ubiquitously expressed member of the coronin protein family in mammals. In fibroblasts and HEK 293 cells, it is localized both in the cytosol and in the submembranous cytoskeleton, especially at lamellipodia and membrane ruffles. The carboxyl terminus of all coronins contains a coiled coil suggested to mediate dimerization. We show here that in contrast to other coronin homologues, the recombinant human coronin 3 carboxyl terminus forms oligomers rather than dimers, and that this part is sufficient to bind to and cross-link F-actin in vitro. The carboxyl terminus alone also conferred membrane association in vivo, and removal of the coiled coil abolished membrane localization but not in vitro F-actin binding. Coronin 3 is exclusively extracted as an oligomer from both the cytosol and the membrane fraction. Because oligomerization was not reported for other coronins, it might be a key feature governing coronin 3-specific functions. Cytosolic coronin 3 showed a high degree of phosphorylation, which is likely to regulate the subcellular localization of the protein.