Abstract:
Chicken drebrin isoforms were first identified in the optic tectum of developing brain. Although the time course of protein expression was different in each drebrin isoform, the similarity between their protein structures was suggested by biochemical analysis of purified protein. To determine their protein structures, the cloning of drebrin cDNAs was conducted. Comparison between the cDNA sequences shows that all drebrin cDNAs are identical except that the internal insertion sequences are present or absent in their sequences. Chicken drebrin are now classified into three isoforms, namely, drebrins E1, E2, and A. Genomic cloning demonstrated that the three isoforms are generated by an alternative splicing of individual exons encoding the insertion sequences from single drebrin gene. The mechanism should be precisely regulated in cell-type-specific and developmental stage-specific fashion. Drebrin protein, which is well conserved in various vertebrate species, although mammalian drebrin has only two isoforms, namely, drebrin E and drebrin A, is different from chicken drebrin that has three isoforms. Drebrin belongs to an actin-depolymerizing factor homology (ADF-H) domain protein family. Besides the ADF-H domain, drebrin has other domains, including the actin-binding domain and Homer-binding motifs. Diversity of protein isoform and multiple domains of drebrin could interact differentially with the actin cytoskeleton and other intracellular proteins and regulate diverse cellular processes.
摘要:
首先在发育中的大脑的视神经顶盖中发现了鸡drebrin亚型。尽管每个drebrin亚型的蛋白质表达的时间过程不同,通过对纯化蛋白质的生化分析,提示了它们的蛋白质结构之间的相似性。为了确定它们的蛋白质结构,进行了drebrincDNA的克隆。cDNA序列之间的比较表明,除了内部插入序列存在或不存在于它们的序列中之外,所有drebrincDNAs是相同的。鸡drebrin现在分为三种亚型,即,drebrinsE1,E2和A。基因组克隆表明,这三种同工型是通过编码单个drebrin基因插入序列的单个外显子的可变剪接产生的。该机制应以细胞类型特异性和发育阶段特异性的方式精确调节。Drebrin蛋白,这在各种脊椎动物物种中都很保守,虽然哺乳动物drebrin只有两种亚型,即,德累林E和德累林A,与具有三种亚型的鸡drebrin不同。Drebrin属于肌动蛋白解聚因子同源(ADF-H)结构域蛋白家族。除了ADF-H域,drebrin还有其他领域,包括肌动蛋白结合结构域和荷马结合基序。drebrin的蛋白质同工型和多个结构域的多样性可以与肌动蛋白细胞骨架和其他细胞内蛋白质差异相互作用,并调节不同的细胞过程。