Kunin Victor, Pereira-Leal José B, Ouzounis Christos A
Computational Genomics Group, The European Bioinformatics Institute EMBL Cambridge Outstation, Cambridge, UK.
Mol Biol Evol. 2004 Jul;21(7):1171-6. doi: 10.1093/molbev/msh085. Epub 2004 Apr 7.
Protein interactions are central to most biological processes. We investigated the dynamics of emergence of the protein interaction network of Saccharomyces cerevisiae by mapping origins of proteins on an evolutionary tree. We demonstrate that evolutionary periods are characterized by distinct connectivity levels of the emerging proteins. We found that the most-connected group of proteins dates to the eukaryotic radiation, and the more ancient group of pre-eukaryotic proteins is less connected. We show that functional classes have different average connectivity levels and that the time of emergence of these functional classes parallels the observed connectivity variation in evolution. We take these findings as evidence that the evolution of function might be the reason for the differences in connectivity throughout evolutionary time. We propose that the understanding of the mechanisms that generate the scale-free protein interaction network, and possibly other biological networks, requires consideration of protein function.
蛋白质相互作用是大多数生物过程的核心。我们通过在进化树上定位蛋白质的起源来研究酿酒酵母蛋白质相互作用网络的出现动态。我们证明，进化时期的特征是新兴蛋白质具有不同的连接水平。我们发现，连接性最强的蛋白质组可追溯到真核生物辐射时期，而更古老的前真核生物蛋白质组的连接性较低。我们表明，功能类别具有不同的平均连接水平，并且这些功能类别的出现时间与进化过程中观察到的连接性变化平行。我们将这些发现作为证据，证明功能的进化可能是整个进化时间内连接性差异的原因。我们提出，要理解产生无标度蛋白质相互作用网络以及可能其他生物网络的机制，需要考虑蛋白质功能。
