Expression level provides important clues about gene function. Previously, various efforts have been undertaken to profile human genes according to their expression level. Intrinsically disordered proteins (IDPs) do not adopt any rigid conformation under physiological conditions, however, are considered as an important functional class in all domains of life. Based on a human tissue-averaged gene expression level, previous studies showed that IDPs are expressed at a lower level than ordered globular proteins. Here, we examined the gene expression pattern of human ordered and disordered proteins in 32 normal tissues. We noticed that in most of the tissues, ordered and disordered proteins are expressed at a similar level. Moreover, in a number of tissues IDPs were found to be expressed at a higher level than ordered proteins. Rigorous statistical analyses suggested that the lower tissue-averaged gene expression level of IDPs (reported earlier) may be the consequence of their biased gene expression in some specific tissues and higher protein length. When we considered the gene repertory of each tissue we noticed that a number of human tissues (brain, testes, etc.) selectively express a higher fraction of disordered proteins, which help them to maintain higher protein connectivity by forming disordered binding motifs and to sustain their functional specificities. Our results demonstrated that the disordered proteins are indispensable in these tissues for their functional advantages.

中文翻译：

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从人类内在失调的蛋白质的基因表达谱中洞悉

表达水平提供了有关基因功能的重要线索。以前，已经进行了各种努力来根据人类基因的表达水平对其进行分析。本质上无序的蛋白质（IDP）在生理条件下不采用任何刚性构象，但是，被认为是生命所有领域中重要的功能类别。根据人类组织平均基因表达水平，以前的研究表明IDP的表达水平低于有序的球状蛋白。在这里，我们检查了人类有序和无序蛋白在32个正常组织中的基因表达模式。我们注意到，在大多数组织中，有序和无序的蛋白质以相似的水平表达。此外，在许多组织中，发现IDP的表达水平高于有序蛋白。严格的统计分析表明，IDPs的组织平均基因表达水平较低（较早报道），可能是由于它们在某些特定组织中的基因表达偏倚和蛋白质长度较高所致。当我们考虑每个组织的基因库时，我们注意到许多人体组织（大脑，睾丸，等）选择性表达较高比例的无序蛋白，这有助于它们形成无序结合基序并维持其功能特异性，从而保持较高的蛋白连接性。我们的结果表明，无序蛋白因其功能优势而在这些组织中必不可少。