Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2025.06.29.662184

Bromodomain protein IBD1 bridges histone acetylation and H2A.Z deposition to fine-tune transcription and prevent hyperactivation in Tetrahymena thermophila

Zhang, Z.·Li, H.·Wei, F.·Ju, A.·Jiang, H.·Ye, F.·Liu, Y.·Gao, S.·Wang, Y.
View original source ↗Export metadata ↓

Abstract

Eukaryotic gene expression is dynamically regulated through the interplay between histone modifications and chromatin remodeling, yet how these processes are coordinated remains incompletely understood. Here, we identify IBD1 as a critical adaptor that bridges histone acetylation and SWR-mediated H2A.Z deposition. We demonstrate that the bromodomain of IBD1 recognizes histone acetylation, specifically H3K9/14 di-acetylation to recruit the SWR complex subunit ARP6, ensuring precise H2A.Z incorporation into chromatin. Genetic disruption of IBD1, either by deletion or bromodomain mutation, attenuates H2A.Z occupancy at target loci, confirming its essential role in H2A.Z deposition. Strikingly, perturbation of the histone acetylation-IBD1-H2A.Z axis triggers transcriptional hyperactivation, revealing a dual function of H2A.Z in sustaining basal transcription while preventing aberrant gene induction. This defines a novel regulatory paradigm in which IBD1 couples acetyl-mark decoding to SWR-dependent H2A.Z deposition, establishing transcriptional homeostasis. Our findings resolve a central ambiguity by demonstrating that H2A.Z acts as a repressive buffer in highly acetylated regions, counterbalancing the inherent activation potential of acetylation. This study provides a framework for investigating H2A.Z functions and reveals new perspectives on how chromatin modifications and histone variants interplay in transcriptional regulation.

Explore related subjects

geneticsPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Zhang, Z., Li, H., Wei, F., Ju, A., Jiang, H., Ye, F., Liu, Y., Gao, S., Wang, Y.. 2025-07-04. Bromodomain protein IBD1 bridges histone acetylation and H2A.Z deposition to fine-tune transcription and prevent hyperactivation in Tetrahymena thermophila. https://doi.org/10.1101/2025.06.29.662184

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Generation of a transgenic cephalopod

Coleoid cephalopods (cuttlefish, octopus, and squid) are marine mollusks with elaborate nervous systems that support a diverse repertoire of complex behaviors. These include the neural control of the color, pattern, and texture of the skin, facilitating both adaptive camouflage and innate patterning that may reflect internal state. The development of transgenic cephalopods expressing fluorescent proteins, optogenetic actuators, and reporters of neural activity would contribute a new and important technology to cephalopod biology. The generation of transgenic cephalopods, however, has remained a major challenge. Here, we report the development of stable transgenic dwarf cuttlefish (Ascarosepion bandense) expressing ubiquitous nuclear-localized mScarlet, a red fluorescent protein. We evaluated multiple strategies for transgenesis, and established cuttlefish lines using both CRISPR and the transposons Sleeping Beauty and Minos. The stable expression of transgenes enabled live imaging of cell dynamics during embryonic development. The Minos transposon emerged as the most efficient transgenesis strategy and is adaptable to promoters and transgenes of choice. These strategies now enable the generation of diverse genetic tools for mechanistic studies of cephalopod biology.

genetics↗
bioRxiv2026

Large language model-based bibliometric evaluation of population descriptors in human genetics

As the use of population descriptors such as race, ethnicity, and ancestry have become increasingly common in modern genetics research, there have been growing calls to critically examine their use. Most notably, in 2023, the National Academies of Science, Engineering, and Medicine (NASEM) published a report titled Using Population Descriptors in Genetics and Genomics Research: A New Framework for an Evolving Field, which included eight specific and actionable recommendations for researchers to implement the ethical and accurate use of population descriptors in genetic research. Here, we use the 2023 NASEM report as a benchmark to analyze the use of population descriptors in genome-wide association studies (GWAS). We develop a general toolkit for large language model-based bibliometrics, operationalize the report's recommendations into an evaluation framework, and apply this framework to evaluate all 4,007 papers from the GWAS Catalog published between 2007 and 2025 with full text available on PubMedCentral. We find significant improvements in adherence to NASEM report recommendations over time. However, most improvements predate the publication of the NASEM report itself, suggesting the report functioned primarily as a synthesis of existing best practices rather than a catalyst for change. We conclude by highlighting opportunities for growth in the field of human genetics.

genetics↗
bioRxiv2026

Mitigating biases of rescaling in forward-in-time population genetic simulations

Forward-in-time population genetic simulations are widely used in evolutionary analyses, but simulating large populations and long genomic regions remains computationally demanding. To reduce this cost, parameter rescaling is widely employed, in which the original evolutionary process is approximated by one with a smaller population size and fewer generations. Recently, several studies using the SLiM simulator have raised concerns about the accuracy of this rescaling approach. In this study, we show that many of the biases reported in these studies can be mitigated by using a different simulation algorithm. These results reveal that the accuracy of parameter rescaling depends on how well the simulation algorithm preserves diffusion-limit properties under rescaling.

genetics↗