Proteins with amino acid homorepeats have the potential to be detrimental to cells and are often associated with human diseases. Why, then, are homorepeats prevalent in eukaryotic proteomes? In yeast, homorepeats are enriched in proteins that are essential and pleiotropic and that buffer environmental insults. The presence of homorepeats increases the functional versatility of proteins by mediating protein interactions and facilitating spatial organization in a repeat-dependent manner. During evolution, homorepeats are preferentially retained in proteins with stringent proteostasis, which might minimize repeat-associated detrimental effects such as unregulated phase separation and protein aggregation. Their presence facilitates rapid protein divergence through accumulation of amino acid substitutions, which often affect linear motifs and post-translational-modification sites. These substitutions may result in rewiring protein interaction and signaling networks. Thus, homorepeats are distinct modules that are often retained in stringently regulated proteins. Their presence facilitates rapid exploration of the genotype–phenotype landscape of a population, thereby contributing to adaptation and fitness.

中文翻译：

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真核蛋白质中氨基酸重复出现的限制和后果

具有氨基酸同源重复的蛋白质有可能对细胞有害，并且通常与人类疾病有关。那么，为什么真核蛋白质组中普遍存在同源重复？在酵母中，同源重复富含必需的和多效性的蛋白质，并且可以缓冲环境损害。同源重复的存在通过介导蛋白质相互作用和以重复依赖的方式促进空间组织，增加了蛋白质的功能多样性。在进化过程中，同源重复优先保留在具有严格蛋白质稳态的蛋白质中，这可能会最大限度地减少重复相关的有害影响，例如不受管制的相分离和蛋白质聚集。它们的存在通过氨基酸取代的积累促进了蛋白质的快速分化，这通常会影响线性基序和翻译后修饰位点。这些替换可能导致重新连接蛋白质相互作用和信号网络。因此，同源重复是不同的模块，通常保留在严格调节的蛋白质中。它们的存在有助于快速探索种群的基因型 - 表型景观，从而有助于适应和适应。