CONCERTED GENE DUPLICATIONS IN THE 2 KERATIN GENE FAMILIES
CONCERTED GENE DUPLICATIONS IN THE 2 KERATIN GENE FAMILIES
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DOI：
10.1007/bf02100075
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发表时间：
1988-01-01
影响因子：
3.9
通讯作者：
BLUMENBERG, M
中科院分区：
文献类型：
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作者：
BLUMENBERG, M
利用简约性系统发育分析（PAUP）程序组，从角蛋白的蛋白质序列推导出进化树。从该分析得出三个主要的意外结论：最小的角蛋白亚基K#19（莫尔等人，1982年）并非最原始的，而是进化以实现一种高度特化的功能，大概是为了纠正角蛋白亚基合成的不平衡。第二，在胚胎早期表达的角蛋白的祖先，K#8和K#18，是最先从所有其他角蛋白的祖先分化出来的。通向这两种角蛋白的分支相对较短，表明对这两种蛋白质序列的变化存在较强的选择作用。第三，两个角蛋白家族在基因复制模式上表现出非凡的平行性。在两个家族中，胚胎中表达的基因首先分化，随后基因复制的爆发产生了在各种分化细胞中表达的亚家族，而相对较近的基因复制产生了毛发角蛋白基因，并将基底细胞特异性角蛋白与在过度增殖条件下表达的角蛋白区分开来。两个角蛋白基因家族中基因复制的平行性意味着一种机制，即一个家族中的复制会影响另一个家族中的复制事件。
Evolutionary trees were derived from the keratin protein sequences using the Phylogeny Analysis Using Parsimony (PAUP) set of programs. Three major unexpected conclusions were derived from the analysis: The smallest keratin protein subunit, K#19 (Moll et al. 1982), is not the most primitive one, but has evolved to fulfill a highly specialized function, presumably to redress the unbalanced synthesis of keratin subunits. Second, the ancestors of keratins expressed in the early embryonic stages, K#8 and K#18, were the first to diverge from the ancestors of all the other keratins. The branches leading to these two keratins are relatively short, indicating a comparatively strong selection against changes in the sequences of these two proteins. Third, the two keratin families show extraordinary parallelism in their patterns of gene duplications. In both families the genes expressed in embryos diverged first, later bursts of gene duplications created the subfamilies expressed in various differentiated cells, and relatively recent gene duplications gave rise to the hair keratin genes and separated the basal cell-specific keratin from those expressed under hyperproliferative conditions. The parallelism of gene duplications in the two keratin gene families implies a mechanism in which duplications in one family influence duplication events in the other family.