Biology subjects

Sura, T.

Publications and source records attributed to Sura, T..

3 recordsLinked to original sources

bioRxiv2026

HERC4 limits oxidative stress-induced DNA damage during bacterial and viral-bacterial infection

Respiratory (co-)infections caused by influenza viruses and Streptococcus pneumoniae represent significant threats to global health. In our analysis of host cell ubiquitination, we identified reactive oxygen species (ROS) produced by S. pneumoniae as critical effectors in reducing the amount of intracellular polyubiquitinated proteins. Together with reduced ubiquitination we observed a downregulation of the E3 ligase HERC4 upon infection with S. pneumoniae in human alveolar epithelial and macrophage-like cells as well as in samples obtained from S. pneumoniae infected humans and mice. This was further aggravated in the viral-bacterial coinfection with influenza A. CRISPR-Cas9 deletion of HERC4 prior bacterial infection resulted in increased ROS-induced DNA damage, enhanced host cell apoptosis and reduced Histone 2B ubiquitination. In contrast, HERC4 overexpression diminished DNA damage indicating a role of HERC4 in DNA-damage-repair upon infection. By establishing a link between HERC4 expression and ROS-induced DNA damage and repair, we identified a potential marker for predicting the outcome of viral and bacterial (co-)infections. Targeting HERC4 expression defines a novel strategy to protect host cells from S. pneumoniae (co-)infection attenuating infection exacerbation.

microbiology↗

bioRxiv2025

Integrated genomic and proteomic analysis of the mouse-adapted Staphylococcus aureus strain JSNZ

Mouse-adapted Staphylococcus aureus strains have become increasingly relevant in infection research thanks to their ability to better recapitulate clinical infection dynamics in mouse models. However, detailed characterisations required to establish a corresponding reference strain are still lacking. The mouse-adapted CC88 strain JSNZ appears to be an ideal candidate for a reference strain, because CC88 is widespread among laboratory mice and frequently employed in mouse colonisation and infection models. Moreover, JSNZ demonstrates high genetic transformability comparable to that of commonly used laboratory strains. Here, we present a comprehensive genomic and proteomic characterisation of JSNZ. Whole genome sequencing was performed using a combination of short and long reads. Proteomic profiling was conducted under standard laboratory conditions in TSB and RPMI during exponential and stationary growth using LC-MS/MS. The updated, closed genome sequence of JSNZ was integrated into AureoWiki for user-friendly access and direct comparison to long-established reference strains. Genome data revealed a deletion in the restriction endonuclease gene hsdR, likely explaining the observed efficient transformation while retaining DNA modification capabilities. This positions JSNZ as a hub for genetic modification of other CC88 isolates. Proteomic profiling of JSNZ indicated broad similarity to common S. aureus reference strains. However, a striking exception was the novel serine protease Jep, which constituted approximately 75% of the exoproteome in stationary TSB cultures. Overall, these findings affirm JSNZ as a robust and genetically tractable model strain for murine S. aureus infection research and contribute a valuable standardised resource to enhance experimental reproducibility and cross-study consistency in the field. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=119 SRC="FIGDIR/small/674026v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@130b864org.highwire.dtl.DTLVardef@199b1f2org.highwire.dtl.DTLVardef@171b6e0org.highwire.dtl.DTLVardef@9d371f_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2023

Homologs of the plastidal preprotein translocase Tic20 mediate organelle assembly in bacteria

Organelle-specific protein translocation systems are essential for organelle biogenesis and maintenance in eukaryotes but thought to be absent from prokaryotic organelles. Here, we identified that MamF-like proteins involved in the formation of bacterial magnetosome organelles share an ancient origin with Tic20 protein translocases found in chloroplasts. Deletion of mamF-like genes in the alphaproteobacterium Magnetospirillum gryphiswaldense results in severe defects in organelle positioning, biomineralization, and magnetic navigation. Consistent with translocase-like functions, these defects are caused by the loss of magnetosome targeting of a subset of organellar proteins containing C-terminal glycine-rich integral membrane domains. Our findings suggest that organelle-specific protein translocation systems may indeed play a role in bacterial organelle formation.

microbiology↗