Multiple actin-based motor genes in Dictyostelium.
Multiple actin-based motor genes in Dictyostelium.
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DOI：
10.1091/mbc.1.1.55
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发表时间：
1989-11
期刊：
影响因子：
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通讯作者：
M. Titus;H. Warrick;J. Spudich
中科院分区：
文献类型：
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作者：
M. Titus;H. Warrick;J. Spudich
与其他分子马达的存在相一致的是，缺乏传统肌球蛋白的Dictyostelials细胞表现出各种各样的运动活动。用包含保守的传统肌球蛋白头部序列的基因片段以低严格性探测Dictyostelials基因组，以确定可能在这些突变细胞的观察到的运动中发挥作用的其他基于肌动蛋白的马达。一个基因(Abma)已被鉴定并编码了一个约135 kDa的多肽，其头部区域与其他肌球蛋白头部序列同源，尾部区域未被预测形成螺旋相互作用的α-螺旋结构。对ABMA、Dictyostelialmyosin I和Acanthamoeba myosins IB和IL的尾部氨基酸序列进行比较，发现在尾部的氨基末端有一个序列相似的区域，可能是一个膜结合区。然而，abma基因并不包含一种不寻常的甘氨酸、Pro、Ala伸展，这是许多先前描述的肌球蛋白的典型特征。用这种方法鉴定了另外两个基因(ABMB和ABMC)，还发现它们含有编码具有典型保守肌球蛋白头部序列的蛋白质的序列。Abm基因可能是一个基于肌动蛋白的马达大家族的一部分，这些马达在细胞运动的不同方面扮演着不同的角色。
Dictyostelium cells, devoid of conventional myosin, display a variety of motile activities, consistent with the presence of other molecular motors. The Dictyostelium genome was probed at low stringency with a gene fragment containing the conserved conventional myosin head domain sequences to identify other actin-based motors that may play a role in the observed motility of these mutant cells. One gene (abmA) has been characterized and encodes a polypeptide of approximately 135 kDa with a head region homologous to other myosin head sequences and a tail region that is not predicted to form either an alpha-helical structure of coiled-coil interactions. Comparisons of the amino acid sequences of the tail regions of abmA, Dictyostelium myosin I, and Acanthamoeba myosins IB and IL reveal an area of sequence similarity in the amino terminal half of the tail that may be a membrane-binding domain. The abmA gene, however, does not contain an unusual Gly, Pro, Ala stretch typical of many of the previously described myosin Is. Two additional genes (abmB and abmC) were identified using this approach and also found to contain sequences that encode proteins with typical conserved myosin head sequences. The abm genes may be part of a large family of actin-based motors that play various roles in diverse aspects of cellular motility.