哺乳动物锌指蛋白家族中KRAB功能域的进化

KRAB锌指基因是哺乳动物中最大的转录调控因子家族,它的多数成员在基因组上成簇分布,具有五种不同的亚家族,在功能行使上承担着不同的作用。本文通过对人类、黑猩猩、小鼠、大鼠和狗五种哺乳动物全蛋白质组序列及mRNA组织表达谱分析,验证了C2H2锌指结构在单个KRAB蛋白质中出现的数目多于一般锌指蛋白质;KRAB功能域在各物种中分布显著不同且与分化时间不成正比,这表明KRAB相关功能域多样性在灵长类进化过程中潜在的适应性进化。同时,提出KRAB亚家族进化的路线：即KRAB—Aa为起始家族,Ba由Aa直接演变形成,而Ca,blonga和XRCC-Z种亚型可能经过Ba或直接从Aa演变形成;此外,锌指结构在单个蛋白质中出现个数伴随KRAB功能域自身的进化路线逐渐递增,反映了KRAB功能域在形成新转录调控因子方面的积极作用。     

The KOX zinc finger genes: genome wide mapping of 368 ZNF PAC clones with zinc finger gene clusters predominantly in 23 chromosomal loci are confirmed by human sequences annotated in EnsEMBL

The chromosome locations of 368 human Kruppel-type zinc finger (ZNF) PAC clones were physically mapped by FISH to human chromosomes in support of recent efforts of assigning KOX cDNAs (KOX1-KOX32) to zinc finger gene clusters. Recent mapping results were validated and confirmed by sequence comparisons to zinc finger gene sequences automatically annotated in EnsEMBL. In toto, 799 Kruppel-type zinc finger genes have been annotated in EnsEMBL of which 290 genes are found to encode KRAB domains. Sequence homologies of the zinc finger domains were used to establish phylogenic trees of KOX zinc finger genes as well as of all KRAB containing human zinc finger and KOX genes documenting the evolution of KRAB zinc finger genes late in primate evolution. A list of 368 assigned ZNF PAC clones is available under http://www.pzr.uni-rostock.de/supplements.