BAYESIAN NETWORK ANALYSIS OF RELATIONSHIPS BETWEEN NUCLEOSOME DYNAMICS AND TRANSCRIPTIONAL REGULATORY FACTORS

Intergenic regions are unstable, owing to trans-regulatory factors that regulate chromatin structure. Nucleosome organisation at promoter has been shown to exhibit distinct patterns corresponding to the level of gene expression. Post-translational modifications (PTMs) of histone proteins and transcriptional regulators, including chromatin remodeling complexes (CRCs), general transcription factors (GTFs), and RNA polymerase II (PolII) arc presumably related to the establishment of such nucleosome dynamics. However, their concrete relationships. especially in gene regulation remain elusive. We. therefore. sought to understand the functional linkages among these factors and nucleosome dynamics by deriving a Bayesian network (BN)-based model representing their interactions. Based on the recovered network learnt from 8 PTMs and 15 transcriptional regulators at 4034 S.cerevisiae promoters, WC speculate that nucleosome organization at promoter is intentionally volatile in various regulatory pathways. Notably, interactions of CRCs/GTFs and H3 hi-tone methylation were inferred to co-function with nucleosome dynamics in gene repression and pre-initiation complex (PIC) formation. Our results affirm the hypothesis that extrinsic factors take part in regulating nucleosome dynamics. More thorough investigation can be made by adding more factors and using our proposed method.