metagene Profiles Analyses Reveal Regulatory Element's Factor-Specific Recruitment Patterns

PLoS Comput Biol. 2016 Aug 18;12(8):e1004751. doi: 10.1371/journal.pcbi.1004751. eCollection 2016 Aug.

Abstract

ChIP-Sequencing (ChIP-Seq) provides a vast amount of information regarding the localization of proteins across the genome. The aggregation of ChIP-Seq enrichment signal in a metagene plot is an approach commonly used to summarize data complexity and to obtain a high level visual representation of the general occupancy pattern of a protein. Here we present the R package metagene, the graphical interface Imetagene and the companion package similaRpeak. Together, they provide a framework to integrate, summarize and compare the ChIP-Seq enrichment signal from complex experimental designs. Those packages identify and quantify similarities or dissimilarities in patterns between large numbers of ChIP-Seq profiles. We used metagene to investigate the differential occupancy of regulatory factors at noncoding regulatory regions (promoters and enhancers) in relation to transcriptional activity in GM12878 B-lymphocytes. The relationships between occupancy patterns and transcriptional activity suggest two different mechanisms of action for transcriptional control: i) a "gradient effect" where the regulatory factor occupancy levels follow transcription and ii) a "threshold effect" where the regulatory factor occupancy levels max out prior to reaching maximal transcription. metagene, Imetagene and similaRpeak are implemented in R under the Artistic license 2.0 and are available on Bioconductor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • B-Lymphocytes / metabolism
  • Cell Line
  • Chromatin Immunoprecipitation / methods*
  • Gene Expression Profiling / methods*
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Metagenomics / methods*
  • Regulatory Sequences, Nucleic Acid / genetics*
  • Software
  • Transcription, Genetic / genetics*

Grants and funding