脊椎动物ABCA基因亚家族研究进展

ABC（ATP-binding cassette）基因家族编码膜蛋白，其成员负责多种物质的跨膜运输。基于氨基酸序列的同源性，人的48个ABC成员被分为7个亚家族：ABCA~ABCG。与其他亚家族相比，ABCA基因编码的蛋白具有独特的拓扑结构，并且其家族成员在两栖动物和哺乳动物分化之后各发生过一次大的扩展（expanding）。基因结构分析发现这两次扩展均是通过基因倍增实现的，这些倍增的产物在啮齿目和食肉目中得到保留，而在灵长目中却有一半变成假基因或被删除。ABCA成员主要负责不同组织器官脂类和胆固醇的跨膜运输，部分成员的突变与疾病相关。

Progress in the Research on the ABCA Gene Family of Vertebrates

The ATP-binding cassette(ABC) superfamily encodes membrane proteins that transport many kinds of substrates across membranes.Based on amino acid sequence similarities and phylogeny,48 ABC genes in the human genome were divided into seven subfamilies: ABCA to ABCG.Among them,ABCA transporters have a unique topology and the members of this subfamily had expanded twice by gene duplication after the divergences between amphibian and mammal,respectively. The new duplicated genes are well retained in rodent and carnivore,while half of them became pseudogenes or were lost in primate genome.Transporters of the ABCA subclass were responsible for critical physiological functions in the transmembrane transportation of endogenous lipid and cholesterol substrates.Mutations of ABCA genes are associated with human genetic diseases.