Pleiotropic Clostridioides difficile Cyclophilin PpiB Controls Cysteine-Tolerance, Toxin Production, the Central Metabolism and Multiple Stress Responses

Abstract

The Gram-positive pathogen Clostridioides difficile is the main bacterial agent of nosocomial antibiotic associated diarrhea. Bacterial peptidyl-prolyl- cis/trans -isomerases (PPIases) are well established modulators of virulence that influence the outcome of human pathologies during infections. Here, we present the first interactomic network of the sole cyclophilin-type PPIase of C. difficile (CdPpiB) and show that it has diverse interaction partners including major enzymes of the amino acid-dependent energy (LdhA, EtfAB, Had, Acd) and the glucose-derived (Fba, GapA, Pfo, Pyk, Pyc) central metabolism. Proteins of the general (UspA), oxidative (Rbr1,2,3, Dsr), alkaline (YloU, YphY) and cold shock (CspB) response were found bound to CdPpiB. The transcriptional (Lrp), translational (InfC, RFF) and folding (GroS, DnaK) control proteins were also found attached. For a crucial enzyme of cysteine metabolism, O -acetylserine sulfhydrylase (CysK), the global transcription regulator Lrp and the flagellar subunit FliC, these interactions were independently confirmed using a bacterial two hybrid system. The active site residues F50, F109, and F110 of CdPpiB were shown to be important for the interaction with the residue P87 of Lrp. CysK activity after heat denaturation was restored by interaction with CdPpiB. In accordance, tolerance toward cell wall stress caused by the exposure to amoxicillin was reduced. In the absence of CdPpiB, C. difficile was more susceptible toward L-cysteine. At the same time, the cysteine-mediated suppression of toxin production ceased resulting in higher cytotoxicity. In summary, the cyclophilin-type PPIase of C. difficile (CdPpiB) coordinates major cellular processes via its interaction with major regulators of transcription, translation, protein folding, stress response and the central metabolism.

Peptidyl-Prolyl Isomerase ppiB Is Essential for Proteome Homeostasis and Virulence in Burkholderia pseudomallei

“…B. pseudomallei is exposed to reactive oxidising species within phagocytes, a natural defence mechanism for eukaryotic cells (57), with loss of ppiB increasing the susceptibility to oxidative stress (Fig 7). Others There are many reports on the pleiotropic effects that immunophilin proteins have in cells, this study demonstrates that virtually every compartment within the cell displays gross proteomic changes, especially those involved in metabolism and genetic information processing (32,34,38,50,62). It has recently been shown by Rasch et al pneumophila (38).…”

Protein sociology of ProA, Mip and other secreted virulence factors at the Legionella pneumophila surface

“…PPIases of pathogens such as Burkholderia, Chlamydia, Clostridium, Neisseria, Klebsiella and others are generally involved in a broad spectrum of phenotypes including virulence, metabolism, and multiple stress responses (Lundemose et al, 1991;Norville et al, 2011;Ünal et al, 2018;Ünal et al, 2019;Christodoulides, 2022;Iwasaki et al, 2022). Likewise, the PPIase Mip of L. pneumophila contributes to infection, collagen binding, phospholipase C-like activity, transmigration across tissue barriers, nematode colonization, surface translocation, and growth at suboptimal temperature (Figure 4) (DebRoy et al, 2006;Ünal et al, 2011;Rasch et al, 2019;Rasch et al, 2016).…”

Editorial: Peptidyl-prolyl cis/trans isomerases (PPIases) in host-pathogen interactions

“…The superfamily of PPIases comprise FK506-binding proteins (FKBPs), cyclophilins, and parvulins and controls a multitude of processes involved in host-pathogen interactions ( Ünal and Steinert, 2014 ). Eukaryotic PPIases play key roles in cancer, neurodegeneration, psychiatric disorders, bacterial and viral infections ( Lee et al., 2011 ; Ünal and Steinert, 2014 ; Blair et al., 2015 ), while bacterial PPIases are involved in metabolism, virulence, and multiple stress responses ( Rasch et al., 2018 ; Ünal et al., 2019 ).…”

“…Although cyclophilins, FKBPs and parvulins are known to influence physiological and pathophysiological processes in pathogens, hosts, and their interactions, only a few natural substrates of these PPIases have been identified ( Ünal et al., 2019 ). However, new methods in interactome research and machine learning seem to improve this situation ( Karagöz et al., 2022 ).…”

“…In this review the hypothesis that host cell PPIases and heat shock proteins are required to facilitate the directed translocation of the enzyme subunits to the cytosol and to assist their refolding into an active conformation is critically evaluated. To what extent bacterial PPIases of Gram-negative and -positive bacteria additionally modulate these processes and if intoxicated patients would benefit from PPIase inhibitors have to be revealed in future research ( Ünal et al., 2018 ; Ünal et al., 2019 ).…”