Different roles of conserved tyrosine residues of the acylated domains in folding and activity of RTX toxins

0547497 - MBÚ 2022 RIV DE eng J - Článek v odborném periodiku
Lepesheva, Anna - Osičková, Adriana - Holubová, Jana - Jurnečka, David - Knoblochová, Šárka - Espinosa-Vinals, Carlos Angel - Bumba, Ladislav - Škopová, Karolína - Fišer, Radovan - Osička, Radim - Šebo, Peter - Mašín, Jiří
Different roles of conserved tyrosine residues of the acylated domains in folding and activity of RTX toxins.
Scientific Reports. Roč. 11, č. 1 (2021), č. článku 19814. ISSN 2045-2322. E-ISSN 2045-2322
Grant CEP: GA MŠMT(CZ) LM2018133; GA ČR(CZ) GA19-12695S; GA ČR(CZ) GX19-27630X; GA ČR(CZ) GA19-04607S
Výzkumná infrastruktura: CIISB II - 90127
Institucionální podpora: RVO:61388971
Klíčová slova: adenylate-cyclase toxin * escherichia-coli hemolysin * bordetella-pertussis cyaa * cell-invasive activity * alpha-hemolysin * membrane translocation * complement receptor-3 * fatty-acylation * calcium * binding
Obor OECD: Biochemistry and molecular biology
Impakt faktor: 4.997, rok: 2021
Způsob publikování: Open access
https://www.nature.com/articles/s41598-021-99112-3

Pore-forming repeats in toxins (RTX) are key virulence factors of many Gram-negative pathogens. We have recently shown that the aromatic side chain of the conserved tyrosine residue 940 within the acylated segment of the RTX adenylate cyclase toxin-hemolysin (CyaA, ACT or AC-Hly) plays a key role in target cell membrane interaction of the toxin. Therefore, we used a truncated CyaA-derived RTX719 construct to analyze the impact of Y940 substitutions on functional folding of the acylated segment of CyaA. Size exclusion chromatography combined with CD spectroscopy revealed that replacement of the aromatic side chain of Y940 by the side chains of alanine or proline residues disrupted the calcium-dependent folding of RTX719 and led to self-aggregation of the otherwise soluble and monomeric protein. Intriguingly, corresponding alanine substitutions of the conserved Y642, Y643 and Y639 residues in the homologous RtxA, HlyA and ApxIA hemolysins from Kingella kingae, Escherichia coli and Actinobacillus pleuropneumoniae, affected the membrane insertion, pore-forming (hemolytic) and cytotoxic capacities of these toxins only marginally. Activities of these toxins were impaired only upon replacement of the conserved tyrosines by proline residues. It appears, hence, that the critical role of the aromatic side chain of the Y940 residue is highly specific for the functional folding of the acylated domain of CyaA and determines its capacity to penetrate target cell membrane.
Trvalý link: http://hdl.handle.net/11104/0323712