The impact of lysine succinylation modification of host factor for RNA phage Qβ replicase at K56 site on the biological functions of Aeromonas hydrophila.

International journal of biological macromolecules [Int J Biol Macromol] 2025 May; Vol. 310 (Pt 1), pp. 143156. Date of Electronic Publication: 2025 Apr 15.

Competing Interests: Declaration of competing interest The authors declare no competing interests.
Post-translational modifications (PTMs) play pivotal roles in modulating protein functions. In Aeromonas hydrophila, a freshwater Gram-negative pathogen threatening human and animal health, the host factor for RNA phage Qβ replicase (Hfq) is a key regulatory protein. Its K56 site undergoes succinylation modification, suggesting important functions. However, the exact roles of Hfq and its K56 site in A. hydrophila were unclear. Our physiological assays showed that hfq deletion increased protease activity and motility, but reduced biofilm formation, chemotaxis, stress response, and antibiotic resistance. K56 succinylation enhanced protease activity and biofilm formation, and altered chemotaxis. Comprehensive transcriptome and proteome analysis further revealed that hfq deletion led to an increase in 11 peptidases and 8 flagellar proteins, as well as a decrease in 5 stress-related proteins. It also suppressed the pathways involved in chemotaxis and beta-lactam resistance. On the other hand, K56 succinylation enhanced fatty acid synthesis pathway and the expression of methyl-accepting chemotaxis proteins (MCPs). Consistent with the omics data, qPCR validation confirmed the expression of 12 genes, including metalloprotease and MCPs. Overall, this study deepened insights into Hfq regulation in A. hydrophila and revealed the previously unknown molecular switch function of post-translational modifications (PTMs) on this protein.
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English

Publisher: Elsevier Country of Publication: Netherlands NLM ID: 7909578 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1879-0003 (Electronic) Linking ISSN: 01418130 NLM ISO Abbreviation: Int J Biol Macromol Subsets: MEDLINE

Aeromonas hydrophila*/metabolism , Aeromonas hydrophila*/genetics , Aeromonas hydrophila*/physiology , Aeromonas hydrophila*/virology , Lysine*/metabolism , Host Factor 1 Protein*/metabolism , Host Factor 1 Protein*/genetics , Host Factor 1 Protein*/chemistry , Bacterial Proteins*/metabolism , Bacterial Proteins*/genetics , Succinic Acid*/metabolism, Protein Processing, Post-Translational ; Biofilms/growth & development ; Chemotaxis ; Gene Expression Regulation, Bacterial ; Proteome ; Transcriptome

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