近日，由中国科学院北京基因组研究所于军研究员和肖景发副研究员及其团队参与完成的国家自然基金和国家重点基础研究发展计划项目——种属特异性小蛋白的功能和进化研究取得新进展，相关研究论文被《生物化学与生物物理进展》（PIBB）网络版接收。
小蛋白（小于个100氨基酸长度的蛋白）在原核和真核生物中广泛存在。但由于计算生物方法和实验技术上存在缺陷，早期针对小蛋白的研究仅仅局限在一些小蛋白家族的功能分析上，并没有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。基因组所较早地开展了针对小蛋白的研究工作，公布了8种真核生物小蛋白功能和进化方面的研究成果。
该研究团队对这8种真核生物的蛋白和潜在的开放阅读框的基因进行全基因组尺度的计算分析，长度小于100氨基酸的蛋白按照序列保守性划分成三类（分别是普遍存在的小蛋白、只存在于脊椎动物的小蛋白和只存在于哺乳动物的小蛋白），余下的是种属特异性小蛋白。研究发现，这三类保守性的蛋白只占很少一部分，而种属特异性小蛋白占大多数。进一步研究人类小蛋白在各组织中的表达情况发现，大多数人类特有的小蛋白也是组织表达特异性的，而那些古老的小蛋白的保守性较强而且在人体各组织中普遍表达。
因此研究人员认为，物种在进化过程中，一些真核小蛋白出现并在自然选择压力下富集，行使不同的特异性功能。（生物谷Bioon.com）
doi:10.1016/j.cell.2011.10.017
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An integrated analysis of lineage-specific small proteins across eight eukaryotes reveals functional and evolutionary significance
ZHAO Qian; XIAO Jing-Fa; YU Jun
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 we report results of our in silico analyses on small proteins (SPs) that include both known SPs and genes with sORFs. Our SPs are defined as RefSeq proteins that shorter than 100 amino acids in length and grouped according to their sequence conservation within lineages of eukaryotes, vertebrates, and mammals. We looked into the biological roles of the grouped SPs and found that they basically perform lineage-specific functions. We also investigated tissue-specificity of human SPs and concluded 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, our results indicated that some of the eukaryotic SPs perform lineage-specific functions and they evolve and express in certain unique ways.
