RT Journal Article
SR Electronic
T1 BiFET: A <span class="underline">Bi</span>as-free Transcription Factor <span class="underline">F</span>ootprint <span class="underline">E</span>nrichment <span class="underline">T</span>est
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 324277
DO 10.1101/324277
A1 Ahrim Youn
A1 Eladio J. Marquez
A1 Nathan Lawlor
A1 Michael L. Stitzel
A1 Duygu Ucar
YR 2018
UL http://biorxiv.org/content/early/2018/05/16/324277.abstract
AB Transcription factor (TF) footprinting uncovers putative protein-DNA binding via combined analyses of chromatin accessibility patterns and their underlying TF sequence motifs. TF footprints are frequently used to identify TFs that regulate activities of cell/condition-specific genomic regions (target loci) in comparison to control regions (background loci) using standard enrichment tests. However, there is a strong association between the chromatin accessibility level and the GC content of a locus and the number and types of TF footprints that can be detected at this site. Traditional enrichment tests (e.g., hypergeometric) do not account for this bias and inflate false positive associations. Therefore, we developed a novel method, Bias-free Footprint Enrichment Test (BiFET), that corrects for the biases arising from the differences in chromatin accessibility levels and GC contents between target and background loci in footprint enrichment analyses. We applied BiFET on TF footprint calls obtained from human EndoC-βH1 ATAC-seq samples using three different algorithms (CENTIPEDE, HINT-BC, and PIQ) and showed BiFET’s ability to increase power and reduce false positive rate when compared to hypergeometric test. Furthermore, we used BiFET to study TF footprints from human PBMC and pancreatic islet ATAC-seq samples to show its utility to identify putative TFs associated with cell-type-specific loci.