Adams M E, Minamide L S, Duester G, Bamburg J R
Department of Biochemistry, Colorado State University, Fort Collins 80523.
Biochemistry. 1990 Aug 14;29(32):7414-20. doi: 10.1021/bi00484a009.
Chick brain actin depolymerizing factor (ADF) is a 19-kDa protein that severs actin filaments and binds actin monomers. We have obtained a cDNA encoding ADF by screening a chick embryo lambda gt11 cDNA library with both a rabbit anti-ADF antiserum and two oligonucleotide probes. Several non-full-length clones of 636 bases and one full-length clone of 1886 bases were isolated and sequenced. The full-length cDNA encodes a protein of 165 amino acids with a calculated molecular weight of 18,520. The deduced amino acid sequence shows 73% identity with the porcine brain actin binding protein cofilin. The coding region of the ADF cDNA has been placed in an expression vector, and the resulting protein shows immunoreactivity with an anti-ADF antiserum but not with an anti-cofilin antibody. The expressed ADF has been purified and has an actin depolymerizing activity identical with that of brain ADF. Like cofilin, ADF contains a sequence similar to the nuclear transport signal sequence of the SV40 large T antigen and a calcium/calmodulin-dependent protein kinase II phosphorylation consensus sequence. Northern blots of both embryonic chick brain and muscle RNA revealed two ADF mRNAs of length 2.1 and 0.9 kilobases. Southern blots suggest that the ADF gene is present in a single copy within the chicken genome. ADF contains regions of homology with other actin binding proteins including tropomyosin, gelsolin, and depactin.
鸡脑肌动蛋白解聚因子（ADF）是一种19 kDa的蛋白质，它能切断肌动蛋白丝并结合肌动蛋白单体。我们通过用兔抗ADF抗血清和两个寡核苷酸探针筛选鸡胚λgt11 cDNA文库，获得了编码ADF的cDNA。分离并测序了几个636个碱基的非全长克隆和一个1886个碱基的全长克隆。全长cDNA编码一个165个氨基酸的蛋白质，计算分子量为18520。推导的氨基酸序列与猪脑肌动蛋白结合蛋白cofilin有73%的同一性。ADF cDNA的编码区已被置于表达载体中，所得蛋白质与抗ADF抗血清有免疫反应，但与抗cofilin抗体没有反应。表达的ADF已被纯化，其肌动蛋白解聚活性与脑ADF相同。与cofilin一样，ADF含有一个与SV40大T抗原的核转运信号序列相似的序列和一个钙/钙调蛋白依赖性蛋白激酶II磷酸化共有序列。对鸡胚脑和肌肉RNA的Northern印迹分析显示有两个长度分别为2.1和0.9千碱基的ADF mRNA。Southern印迹分析表明ADF基因在鸡基因组中以单拷贝形式存在。ADF与其他肌动蛋白结合蛋白包括原肌球蛋白、凝溶胶蛋白和去聚合蛋白有同源区域。
