Thioloxidoreductase HP0231 of Helicobacter pylori impacts HopQ-dependent CagA translocation

Thioloxidoreductase HP0231 of Helicobacter pylori plays essential roles in gastric colonization and related gastric pathology. Comparative proteomics and analysis of complexes between HP0231 and its protein substrates suggested that several Hop proteins are its targets. HP0231 is a dimeric oxidoreductase that functions in an oxidizing Dsb (disulfide bonds) pathway of H. pylori. H. pylori HopQ possesses six cysteine residues, which generate three consecutive disulfide bridges. Comparison of the redox state of HopQ in wild-type cells to that in hp0231-mutated cells clearly indicated that HopQ is a substrate of HP0231. HopQ binds CEACAM1, 3, 5 and 6 (carcinoembryonic antigen-related cell adhesion molecules). This interaction enables T4SS-mediated translocation of CagA into host cells and induces host signaling. Site directed mutagenesis of HopQ (changing cysteine residues into serine) and analysis of the functioning of HopQ variants showed that HP0231 influences the delivery of CagA into host cells, in part through its impact on HopQ redox state. Introduction of a C382S mutation into HopQ significantly affects its reaction with CEACAM receptors, which disturbs T4SS functioning and CagA delivery. An additional effect of HP0231 on other adhesins and their redox state, resulting in their functional impairment, cannot be excluded

Poróumanie wpływu różnych sposobów wprowadzania wapnia na występowanie suchej zgnilizny wierzchołków owoców pomidorów [Comparison of the different ways of treatment with calcium on the occurrence of blossom-end rot of tomato fruits]

Repeated spraying of tomato fruit with 1% CaCl2 • 6H2O protects them from dry rot of fruit but the spraying of leaves alone has no effect on disease. Too frequent spraying with anhydrous 1% CaCl2 of whole plants may damage leaves and diminish yield

Wpływ kilku retardantów wzrostu roślin na plon oraz zawartość azotanów i aktywność peroksydazy i oksydazy polifenolowej w owocach trzech odmian pomidorów [The influence of some growth retardants on yield and contents nitrates and activity of peroxidase and polyphenyloxidase by fruit of three tomato varieties]

In 1969 year the influence of five retardants (CCC, B995 RW78, RW82, RW85 on tomato varieties ('Maria', 'Fireball' and 'Earliest of All') was tested. It was found that CCC and B985 greatly retarded the growth of these three varieties. The retardant B995 delayed and CCC promoted flowering of tomato plants. In the 'Maria' variety CCC increased and B995 decreased early yield. All five agents had no significant influence of the total yield. All the chemicals had a significant influence on the activity of peroxidase and polyphenyloxidase and the content of nitrates in the tomato fruits, but response of the particular varieties differed

Interplay between DsbA1, DsbA2 and C8J1298 Periplasmic Oxidoreductases of Campylobacter jejuni and Their Impact on Bacterial Physiology and Pathogenesis

The bacterial proteins of the Dsb family catalyze the formation of disulfide bridges between cysteine residues that stabilize protein structures and ensure their proper functioning. Here, we report the detailed analysis of the Dsb pathway of Campylobacter jejuni. The oxidizing Dsb system of this pathogen is unique because it consists of two monomeric DsbAs (DsbA1 and DsbA2) and one dimeric bifunctional protein (C8J_1298). Previously, we showed that DsbA1 and C8J_1298 are redundant. Here, we unraveled the interaction between the two monomeric DsbAs by in vitro and in vivo experiments and by solving their structures and found that both monomeric DsbAs are dispensable proteins. Their structures confirmed that they are homologs of EcDsbL. The slight differences seen in the surface charge of the proteins do not affect the interaction with their redox partner. Comparative proteomics showed that several respiratory proteins, as well as periplasmic transport proteins, are targets of the Dsb system. Some of these, both donors and electron acceptors, are essential elements of the C. jejuni respiratory process under oxygen-limiting conditions in the host intestine. The data presented provide detailed information on the function of the C. jejuni Dsb system, identifying it as a potential target for novel antibacterial molecules