Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, 900 North Glebe Road, Arlington, VA, 22203, USA.
Center for Computational Biology, Flatiron Institute, Simons Foundation, 162 Fifth Avenue, New York, NY, 10010, USA.
BMC Bioinformatics. 2021 Apr 15;22(1):193. doi: 10.1186/s12859-021-04108-5.
ChIP-seq combines chromatin immunoprecipitation assays with sequencing and identifies genome-wide binding sites for DNA binding proteins. While many binding sites have strong ChIP-seq 'peak' observations and are well captured, there are still regions bound by proteins weakly, with a relatively low ChIP-seq signal enrichment. These weak binding sites, especially those at promoters and enhancers, are functionally important because they also regulate nearby gene expression. Yet, it remains a challenge to accurately identify weak binding sites in ChIP-seq data due to the ambiguity in differentiating these weak binding sites from the amplified background DNAs.
ChIP-BIT2 ( http://sourceforge.net/projects/chipbitc/ ) is a software package for ChIP-seq peak detection. ChIP-BIT2 employs a mixture model integrating protein and control ChIP-seq data and predicts strong or weak protein binding sites at promoters, enhancers, or other genomic locations. For binding sites at gene promoters, ChIP-BIT2 simultaneously predicts their target genes. ChIP-BIT2 has been validated on benchmark regions and tested using large-scale ENCODE ChIP-seq data, demonstrating its high accuracy and wide applicability.
ChIP-BIT2 is an efficient ChIP-seq peak caller. It provides a better lens to examine weak binding sites and can refine or extend the existing binding site collection, providing additional regulatory regions for decoding the mechanism of gene expression regulation.
ChIP-seq 将染色质免疫沉淀实验与测序相结合，从而鉴定出 DNA 结合蛋白在全基因组范围内的结合位点。虽然许多结合位点具有较强的 ChIP-seq“峰”观察值，并且能够很好地捕获，但仍有一些蛋白质较弱地结合在这些区域，其 ChIP-seq 信号富集程度相对较低。这些较弱的结合位点，尤其是那些位于启动子和增强子上的结合位点，具有重要的功能，因为它们也调节附近基因的表达。然而，由于难以区分这些较弱的结合位点与扩增背景 DNA，因此仍然难以在 ChIP-seq 数据中准确识别较弱的结合位点。
ChIP-BIT2（http://sourceforge.net/projects/chipbitc/）是一个用于 ChIP-seq 峰检测的软件包。ChIP-BIT2 采用了一种混合模型，该模型整合了蛋白质和对照 ChIP-seq 数据，并预测了启动子、增强子或其他基因组位置上的强或弱蛋白结合位点。对于基因启动子上的结合位点，ChIP-BIT2 同时预测了它们的靶基因。ChIP-BIT2 已经在基准区域进行了验证，并使用大规模 ENCODE ChIP-seq 数据进行了测试，证明了其具有较高的准确性和广泛的适用性。
ChIP-BIT2 是一种高效的 ChIP-seq 峰调用器。它为研究较弱的结合位点提供了更好的视角，并可以对现有的结合位点集进行细化或扩展，为解码基因表达调控机制提供更多的调控区域。
