Biology subjects

Bannister, A. J.

Publications and source records attributed to Bannister, A. J..

3 recordsLinked to original sources

bioRxiv2025

METTL9 sustains vertebrate neural development primarily via non-catalytic functions

METTL9 is an enzyme catalysing N1-methylation of histidine residues (1MH) within eukaryotic proteins. Given its high expression in vertebrate nervous system and its potential association with neurodevelopmental delay, we dissected Mettl9 role during neural development. We generated three distinct mouse embryonic stem cell lines: a complete Mettl9 knock-out (KO), an inducible METTL9 Degron and a line endogenously expressing a catalytically inactive protein, and assessed their ability to undergo neural differentiation. In parallel, we down-regulated mettl9 in Xenopus laevis embryos and characterised their neural development. Our multi-omics data indicate that METTL9 exerts a conserved role in sustaining vertebrate neurogenesis. This is largely independent of its catalytic activity and occurs through modulation of the secretory pathway. METTL9 interacts with key regulators of cellular transport, endocytosis and Golgi integrity; moreover, in Mettl9KO cells Golgi becomes fragmented. Overall, we discovered the first developmental function of Mettl9 and linked it to a 1MH-independent pathway, namely, the maintenance of the secretory system, which is essential throughout neural development.

developmental biology↗

bioRxiv2024

PhOxi-seq detects enzyme-dependent m2G in multiple RNA types

In recent years, RNA-modifying enzymes have gained significant attention due to their impact on critical RNA-based processes, and consequently human pathology. However, identifying sites of modifications throughout the transcriptome remains challenging largely due to the lack of accurate and sensitive detection technologies. Recently, we described PhOxi-seq as a method capable of confirming known sites of m2G within abundant classes of RNA, namely purified rRNA and purified tRNA. Here, we further explore the selectivity of PhOxi-seq and describe an optimised PhOxi-seq workflow, coupled to a novel bioinformatic pipeline, that is capable of detecting enzyme-dependent m2G sites throughout the transcriptome, including low abundant mRNAs. In this way, we generated the first database of high confidence sites of THUMPD3-dependent m2G in multiple RNA classes within a human cancer cell line and further identify non-THUMPD3 controlled sites throughout the transcriptome.

biochemistry↗

bioRxiv2020

Viral mimicry of p65/RelA transactivation domain to inhibit NF-κB activation

Sensing of virus infection activates NF-{kappa}B to induce the expression of interferons, cytokines and chemokines to initiate the antiviral response. Viruses antagonise these antiviral defences by interfering with immune sensing and blocking the actions of antiviral and inflammatory molecules. Here, we show that a viral protein mimics the transactivation domain of the p65 subunit of NF-{kappa}B. The C terminus of vaccinia virus (VACV) protein F14 (residues 51-73) activates transcription when fused to a DNA-binding domain-containing protein and F14 associates with NF-{kappa}B co-activator CBP, disrupting p65-CBP interaction. Consequently, F14 diminishes CBP-mediated acetylation of p65 and the downstream recruitment of the transcriptional regulator BRD4 to the promoter of the NF-{kappa}B-responsive genes CXCL10 and CCL2, hence inhibiting their expression. Conversely, the recruitment of BRD4 to the promoters of NFKBIA, which encodes the inhibitor of NF-{kappa}B (I{kappa}B), and CXCL8 remains unaffected in the presence of either F14 or JQ1, a competitive inhibitor of BRD4 bromodomains, indicating its recruitment is acetylation-independent. Therefore, unlike other viral NF-{kappa}B antagonists, F14 is a selective inhibitor of NF-{kappa}B-dependent gene expression. A VACV strain lacking F14 showed that it contributes to virulence in an intradermal model of infection. Our results uncover a mechanism by which viruses disarm the antiviral defences through molecular mimicry of a conserved host protein and provide insight into the regulation of NF-{kappa}B-dependent gene expression by BRD4.

microbiology↗