Xenopus laevis integrins. Structural conservation and evolutionary divergence of integrin beta subunits.
Xenopus laevis integrins. Structural conservation and evolutionary divergence of integrin beta subunits.
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DOI：
10.1016/s0021-9258(18)60720-3
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发表时间：
1988-04
期刊：
影响因子：
--
通讯作者：
D. DeSimone;R. Hynes
中科院分区：
文献类型：
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作者：
D. DeSimone;R. Hynes
我们报道了从非洲爪蟾（Xenopus laevis neurula） cDNA文库中分离的两个不同整合素β亚基的cDNA克隆序列。与这两个基因相对应的mrna首先在原肠胚形成时被检测到。我们发现这两个β亚基高度相关（98%的氨基酸序列相同），可能出现在大约5000万年前的X. laevis基因组四倍体化时期。将这些序列与其他各种脊椎动物整合素β亚基的序列进行比较，发现迄今为止分析的所有物种都含有高度保守的整合素β亚基（β 1）。这类整合素β亚基的种间同源性（82-86%的氨基酸序列同源性）远高于人类已知的三种不同的整合素β亚基（40-48%的氨基酸序列同源性）。同源性分析清楚地表明，在脊椎动物出现之前的5亿多年前，这个多基因家族就存在重复和分化。我们还观察到鸡整合素β亚基的cDNA探针与几种无脊椎动物的基因组dna之间的交叉杂交。尽管不同的整合素β亚基在序列上存在差异，但其结构的某些特征是非常保守的。
We report the sequences of cDNA clones for two different integrin beta subunits isolated from a Xenopus laevis neurula cDNA library. mRNAs corresponding to both genes are first detected at gastrulation. We show that these two beta subunits are very highly related (98% identity in amino acid sequence) and probably arose at the time of tetraploidization of the X. laevis genome around 50 million years ago. Comparison of these sequences with those of various other vertebrate integrin beta subunit establishes that all species analyzed to date contain a highly conserved integrin beta subunit (beta 1). The interspecies homologies within this class of integrin beta subunits (82-86% identity in amino acid sequence) are much greater than those among the three different beta subunits which are known in humans (40-48% identity in amino acid sequence). Analysis of the homologies clearly indicates duplication and divergence of this multigene family more than 500 million years ago prior to the appearance of the vertebrates. We also observe cross-hybridization between cDNA probes for chicken integrin beta subunits and genomic DNAs of several invertebrate species. Despite the divergence in sequence among different integrin beta subunits, certain features of their structure are remarkably conserved.