arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1302.4424q-bio.GNcond-mat.dis-nnphysics.bio-phq-bio.QM
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超越位置权重矩阵:转录因子结合位点的核苷酸相关性及其描述

Beyond position weight matrices: nucleotide correlations in transcription factor binding sites and their description

Marc Santolini, Thierry Mora, Vincent Hakim

摘要:

基因组DNA上转录因子结合位点(TFBS)的识别对于理解和预测基因网络中的调控元件具有重要意义。TFBS基序通常由位置权重矩阵(PWMs)描述,其中每个DNA碱基对独立地有助于转录因子(TF)结合,尽管越来越多的证据表明碱基对位置之间的相互依赖性。最近关于TF结合DNA区域的全基因组数据的可用性提供了重新详细讨论TF结合{ \em in vivo}的这个问题的可能性。在这里,我们使用了可用的苍蝇和小鼠ChIPseq数据,并表明独立模型通常不会重现TFBS的观察统计数据,从而概括了以前的观察结果。我们进一步表明,TFBS的描述和可预测性可以系统地提高考虑成对相关性的TFBS通过最大熵的原则。由此产生的成对相互作用模型是正式等效的无序波茨模型的统计力学,它概括了以前的方法相互依赖的位置。它的结构允许两个或更多个碱基对的共变异,以及二级基序。虽然模型组成的混合物的PWM也有这最后一个功能,我们表明,成对的相互作用模型优于它们。显着的成对相互作用被发现是稀疏的,并发现占主导地位的连续碱基对之间。最后,使用一个成对的相互作用模型的识别TFBS的显示给显着不同的预测比一个模型的基础上独立的位置。

英文摘要:

The identification of transcription factor binding sites (TFBSs) on genomic DNA is of crucial importance for understanding and predicting regulatory elements in gene networks. TFBS motifs are commonly described by Position Weight Matrices (PWMs), in which each DNA base pair independently contributes to the transcription factor (TF) binding, despite mounting evidence of interdependence between base pairs positions. The recent availability of genome-wide data on TF-bound DNA regions offers the possibility to revisit this question in detail for TF binding {\em in vivo}. Here, we use available fly and mouse ChIPseq data, and show that the independent model generally does not reproduce the observed statistics of TFBS, generalizing previous observations. We further show that TFBS description and predictability can be systematically improved by taking into account pairwise correlations in the TFBS via the principle of maximum entropy. The resulting pairwise interaction model is formally equivalent to the disordered Potts models of statistical mechanics and it generalizes previous approaches to interdependent positions. Its structure allows for co-variation of two or more base pairs, as well as secondary motifs. Although models consisting of mixtures of PWMs also have this last feature, we show that pairwise interaction models outperform them. The significant pairwise interactions are found to be sparse and found dominantly between consecutive base pairs. Finally, the use of a pairwise interaction model for the identification of TFBSs is shown to give significantly different predictions than a model based on independent positions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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