The carboxy terminus of AFAP-110 modulates direct interactions with actin filaments and regulates its ability to alter actin filament integrity and induce lamellipodia formation
The carboxy terminus of AFAP-110 modulates direct interactions with actin filaments and regulates its ability to alter actin filament integrity and induce lamellipodia formation
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DOI：
10.1006/excr.1999.4795
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发表时间：
2000-02-25
影响因子：
3.7
通讯作者：
Flynn, DC
中科院分区：
文献类型：
--
作者：
Qian, Y;Baisden, JM;Flynn, DC
肌动蛋白丝相关蛋白 AFAP-110 是 Src 的 SH2/SH3 结合伴侣。 AFAP-110 在其氨基末端含有多个蛋白质结合基序，并被假设为可将信号蛋白与肌动蛋白丝连接起来的衔接分子。最近使用缺失诱变的研究表明，AFAP-110 可以改变 SV40 转化的 Cos-1 细胞中肌动蛋白丝的完整性。因此，AFAP-110可以调节Src对肌动蛋白丝的作用。在本报告中，我们试图确定 (a) AFAP-110 是否可以直接与肌动蛋白丝相互作用，以及 (b) 缺失突变体是否可以影响未转化的成纤维细胞中肌动蛋白丝的完整性和细胞形状。数据表明，AFAP-110 的羧基末端对于体内和体外肌动蛋白丝缔合来说既是必要的也是充分的。对羧基末端的分析揭示了与其他已知肌动蛋白结合基序的平均 40% 相似性，表明了与肌动蛋白丝结合的机制。 AFAP-110 还可以诱导片状伪足的形成。与α螺旋、肌动蛋白结合基序相邻的是α螺旋、亮氨酸拉链基序。删除亮氨酸拉链基序 (AFAP(Delta lzip))，然后进行细胞表达，使 AFAP(Delta lzip) 能够改变未转化细胞中肌动蛋白丝的完整性和细胞形状，这一点可以通过诱导片状伪足形成来证明。我们假设 AFAP-110 可能是一种重要的信号蛋白，可以直接调节肌动蛋白丝完整性的变化并诱导片状伪足的形成。 (C) 2000 年学术出版社。
The actin filament-associated protein AFAP-110 is an SH2/SH3 binding partner for Src. AFAP-110 contains several protein-binding motifs in its amino terminus and has been hypothesized to function as an adaptor molecule that could link signaling proteins to actin filaments. Recent studies using deletional mutagenesis demonstrated that AFAP-110 can alter actin filament integrity in SV40 transformed Cos-1 cells. Thus, AFAP-110 may be positioned to modulate the effects of Src upon actin filaments. In this report, we sought to determine whether (a) AFAP-110 could interact with actin filaments directly and (b) deletion mutants could affect actin filament integrity and cell shape in untransformed fibroblast cells. The data demonstrate that the carboxy terminus of AFAP-110 is both necessary and sufficient for actin filament association, in. Dine and in vitro. Analysis of the carboxy terminus revealed a mean 40% similarity with other known actin-binding motifs, indicating a mechanism for binding to actin filaments. AFAP-110 can also induce lamellipodia formation. Contiguous with the alpha-helical, actin-binding motif is an alpha-helical, leucine zipper motif. Deletion of the leucine zipper motif (AFAP(Delta lzip)) followed by cellular expression enabled AFAP(Delta lzip) to alter actin filament integrity and cell shape in untransformed cells as evidenced by the induction of lamellipodia formation. We hypothesize that AFAP-110 may be an important signaling protein that can directly modulate changes in actin filament integrity and induce lamellipodia formation. (C) 2000 Academic Press.