MEPP: more transparent motif enrichment by profiling positional correlations.

Area of Science:

• Genomics and Bioinformatics
• Molecular Biology
• Computational Biology

Background:

• Score-based motif enrichment analysis (MEA) identifies transcription factors (TFs) regulating DNA but often ignores motif position relative to functional elements.
• Key DNA anchor points, such as transcription start sites (TSS) or other motifs, can influence TF binding and function in a distance-dependent manner.
• Existing MEA methods lack the ability to profile motif enrichment in relation to these critical positional features.

Purpose of the Study:

• To develop a novel MEA method, Motif Enrichment Positional Profiling (MEPP), that incorporates positional information of TF binding motifs.
• To profile the enrichment of TF binding motifs relative to specific anchor points within DNA sequences.
• To account for nucleotide bias in sequence analysis for more accurate motif enrichment profiling.

Main Methods:

• Developed MEPP, a novel MEA method that generates positional enrichment profiles for TF binding motifs.
• MEPP analyzes motif presence relative to user-defined anchor points (e.g., TSS, other motifs).
• The method incorporates a correction for lower-order nucleotide bias in sequence data.

Main Results:

• Demonstrated MEPP's utility in identifying sequence positions where motif presence correlates with biological activity, using transcription initiation and TF binding as test cases.
• Showcased MEPP's ability to infer positional dependencies of TF binding site function.
• Validated MEPP's application in interpreting experimental data from transcription initiation, chromatin structure, and TF binding assays.

Conclusions:

• MEPP provides a powerful new approach for motif enrichment analysis by incorporating positional information.
• The method enhances the interpretation of TF binding and regulatory DNA function by revealing positional dependencies.
• MEPP facilitates hypothesis generation for experiments investigating gene regulation and molecular interactions.