MODULATION OF SPECTRIN ACTIN ASSEMBLY BY ERYTHROCYTE ADDUCIN
MODULATION OF SPECTRIN ACTIN ASSEMBLY BY ERYTHROCYTE ADDUCIN
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DOI：
10.1038/328359a0
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发表时间：
1987-07-23
期刊：
影响因子：
64.8
通讯作者：
BENNETT, V
中科院分区：
文献类型：
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作者：
GARDNER, K;BENNETT, V
以光谱为基础的膜骨架是一种与质膜紧密相关的蛋白质组合，它决定了红细胞的形状和力学特性。Spectrin是这一组合中最丰富的成分，是一种细长而灵活的分子，在蛋白4.1的增强作用下，在其末端通过短肌动蛋白丝交联，在膜下形成晶格。这些蛋白质和其他蛋白质稳定质膜，组织完整的膜蛋白并维持细胞表面的特殊区域1,3。红细胞的膜-骨架相关钙调素结合蛋白4是Ca2+和磷脂依赖性蛋白激酶C的主要底物（参考文献5），因此是Ca2+的两种调节途径的靶标。在这里，我们证明了这种称为内收蛋白的蛋白质：(1)在体外与幽灵蛋白-肌动蛋白复合物紧密结合，但与幽灵蛋白或单独的肌动蛋白的亲和力要小得多；(2)促进额外的谱蛋白分子组装到肌动蛋白丝上；(3)在微摩尔浓度的钙调蛋白和Ca2+的作用下，其诱导额外谱蛋白分子与肌动蛋白结合的能力受到抑制。内收蛋白可能参与Ca2+在红细胞膜骨架上的作用和谱蛋白-肌动蛋白复合物的组装。
The spectrin-based membrane skeleton, an assembly of proteins tightly associated with the plasma membrane, determines the shape and mechanical properties of erythrocytes. Spectrin, the most abundant component of this assembly, is an elongated and flexible molecule that, with potentiation by protein 4.1, is cross-linked at its ends by short actin filaments to form a lattice beneath the membrane. These and other proteins stabilize the plasma membrane, organize integral membrane proteins and maintain specialized regions of the cell surface1,3. A membrane-skeleton-associated calmodulin-binding protein of erythrocytes4is a major substrate for Ca2+- and phospholipid-dependent protein kinase C (ref. 5), and thus is a target for Ca2+by two regulatory pathways. Here we demonstrate that this protein, called adducin: (1) binds tightly in vitro to spectrin-actin complexes but with much less affinity either to spectrin or to actin alone; (2) promotes assembly of additional spectrin molecules onto actin filaments; and (3) is inhibited in its ability to induce the binding of additional spectrin molecules to actin by micromolar concentrations of calmodulin and Ca2+. Adducin may be involved in the action of Ca2+on erythrocyte membrane skeleton and in the assembly of spectrin-actin complexes.