基于8种真核生物的整合分析揭示种属特异性小蛋白的功能和进化特征(英文)

An Integrated Analysis of Lineage-specific Small Proteins Across Eight Eukaryotes Reveals Functional and Evolutionary Significance

小蛋白(<100个氨基酸)广泛存在于三界生命中,具有重要生物功能.早期涉及小蛋白的研究主要集中于少量特殊物种中的蛋白质家族,以及在全基因组尺度预测短小开放读码框(sORFs)的算法开发,但并无跨真核物种的大规模组学分析来揭示小蛋白的功能和进化特征.通过对已知小蛋白和拥有短小开放读码框的基因进行全基因组尺度的计算分析,长度小于100个氨基酸的RefSeq proteins按照其序列保守性被划分为存在于所有8种真核生物、只存在于脊椎动物和只存在于哺乳动物三个进化分类中,此三个进化分类所对应的生物学功能揭示了小蛋白行使种属特异性功能的特征.进一步研究发现,大多数人类特有的小蛋白也是组织表达特异性的,并且绝大多数古老的小蛋白在人体内普遍表达.因此认为,一些真核小蛋白出现并在自然选择压力下富集,行使种属特异性功能,并且以特殊的方式进化和表达.

Small proteins（ 〈100 amino acids） are prevalent in all three domains of life.Earlier studies have been focusing on a limited number of small protein families in specific organisms and developing genome-wide algorithms to identify short open-reading-frames or sORFs.Here the in silico analyses on small proteins（SPs） include both known SPs and genes with sORFs.RefSeq proteins that shorter than 100 amino acids in length are defined as SPs and are grouped according to their sequence conservation within lineages of eukaryotes,vertebrates,and mammals.Biological roles of the grouped SPs are found basically performing lineage-specific functions.Tissue-specificity of human SPs are also investigated and showed that a majority of the human-specific SPs are tissue-specific and that most of the human SPs originated after the split of vertebrates and invertebrates are mostly universally expressed.In addition,the results indicated that some of the eukaryotic SPs perform lineage-specific functions and they evolve and express in certain unique ways.