Live-cell functions of histone PTM readers and histone H2A.Z variant in epigenetic regulation of transcription

Eukaryotic gene expression is tightly regulated by chromatin architecture, which is influenced by histone post- translational modifications (PTMs) and the incorporation of histone variants such as H2A.Z. These modifications can alter chromatin structure, thereby modulating gene accessibility and transcriptional activity. Despite their significance, the precise mechanisms by which histone PTM readers and H2A.Z function in living cells remain poorly understood. This project aims to elucidate the physiological functions of histone PTM readers and H2A.Z in transcription regulation using live-cell, single-molecule imaging and genomic approaches in budding yeast. We hypothesize that histone PTM readers and H2A.Z dynamically influence chromatin remodeling and transcription factor recruitment during transcription initiation and elongation. Aim 1 will investigate the role of histone PTM readers in targeting chromatin remodelers, focusing on bromodomain- and YEATS-containing proteins within the SWR1, INO80, and SWI/SNF complexes. Aim 2 will define the impact of H2A.Z on the recruitment and stability of transcription initiation and elongation factors, determining whether it facilitates pre-initiation complex (PIC) assembly and RNA polymerase II elongation. Aim 3 will explore the role of H2A.Z in transcription bursting using live-cell single-RNA imaging, examining its impact on transcriptional kinetics and gene activation. By integrating quantitative single-molecule tracking, genomic mapping, and genetic perturbation, this research will provide fundamental insights into how chromatin-associated factors regulate transcription dynamics. The findings will enhance our understanding of eukaryotic gene regulation and have broad implications for chromatin biology and disease-related transcriptional dysregulation. Project Number: 1R01GM164639-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of General Medical Sciences (NIGMS) | Principal Investigator: Anand Ranjan | Institution: JOHNS HOPKINS UNIVERSITY, BALTIMORE, MD | Award Amount: $326,463 | Activity Code: R01 | Study Section: Molecular Genetics Study Section[MG] View on NIH RePORTER: https://reporter.nih.gov/project-details/11346916