Cyclophilin and Trigger Factor fromBacillussubtilisCatalyze in Vitro Protein Folding and Are Necessary for Viability under Starvation Conditions†

Biochemistry ◽  
1998 ◽  
Vol 37 (38) ◽  
pp. 13392-13399 ◽  
Author(s):  
Sven F. Göthel ◽  
Christian Scholz ◽  
Franz X. Schmid ◽  
Mohamed A. Marahiel
2021 ◽  
Author(s):  
Rebecca A. Keogh ◽  
Rachel L. Zapf ◽  
Andrew Frey ◽  
Emily C. Marino ◽  
Gillian G. Null ◽  
...  

Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that assist in protein folding around proline-peptide bonds, and often possess chaperone activity. Staphylococcus aureus encodes three PPIases; PrsA, PpiB and Trigger factor (TF). Previous work by our group demonstrated a role for both PrsA and PpiB in S. aureus, however, TF remains largely unstudied. Here, we identify a role for TF in S. aureus biofilm formation, and demonstrate cooperation between TF and the cytoplasmic PPIase PpiB. Mutation of the tig gene (encoding TF) leads to reduced biofilm development in vitro but no significant attenuation of virulence in a mouse model of infection. To investigate if TF possesses chaperone activity, we analyzed the ability of a tig mutant to survive acid and basic stress. While there was no significant decrease in a tig mutant, a ppiB/tig double mutant exhibited a significant decrease in cell viability after acid and base challenge. We then demonstrate that a ppiB/tig double mutant has exacerbated phenotypes in vitro and in vivo when compared to either single mutant. Finally, in vivo immunoprecipitation of epitope tagged PpiB reveals that PpiB interacts with four times the number of proteins when TF is absent from the cell, suggesting it may be compensating for the loss of TF. Interestingly, the only proteins found to interact with TF are TF itself, FnBPB and the chaperone protein ClpB. Collectively, these results support the first phenotype for S. aureus TF and demonstrate a greater network of cooperation between chaperone proteins in Staphylococcus aureus. IMPORTANCE S. aureus encodes a large number of virulence factors that aid the bacterium in survival and pathogenesis. These virulence factors have a wide variety of functions, however, they must all be properly secreted in order to be functional. Bacterial chaperone proteins often assist in secretion by trafficking proteins to secretion machinery or assisting in proper protein folding. Here, we report that the S. aureus chaperone Trigger factor (TF) contributes to biofilm formation and cooperates with the chaperone PpiB to regulate S. aureus virulence processes. These data highlight the first known role for TF in S. aureus, and suggest that S. aureus chaperone proteins may be involved in a greater regulatory network in the cell.


2008 ◽  
Vol 366 (2) ◽  
pp. 598-603 ◽  
Author(s):  
Arunima Basu ◽  
Dibyendu Samanta ◽  
Debasis Das ◽  
Saheli Chowdhury ◽  
Arpita Bhattacharya ◽  
...  

1996 ◽  
Vol 235 (3) ◽  
pp. 613-621 ◽  
Author(s):  
Biswadip Das ◽  
Subrata Chattopadhyay ◽  
Aloke Kumar Bera ◽  
Chanchal DasGupta

2019 ◽  
Vol 26 (5) ◽  
pp. 339-347 ◽  
Author(s):  
Dilani G. Gamage ◽  
Ajith Gunaratne ◽  
Gopal R. Periyannan ◽  
Timothy G. Russell

Background: The dipeptide composition-based Instability Index (II) is one of the protein primary structure-dependent methods available for in vivo protein stability predictions. As per this method, proteins with II value below 40 are stable proteins. Intracellular protein stability principles guided the original development of the II method. However, the use of the II method for in vitro protein stability predictions raises questions about the validity of applying the II method under experimental conditions that are different from the in vivo setting. Objective: The aim of this study is to experimentally test the validity of the use of II as an in vitro protein stability predictor. Methods: A representative protein CCM (CCM - Caulobacter crescentus metalloprotein) that rapidly degrades under in vitro conditions was used to probe the dipeptide sequence-dependent degradation properties of CCM by generating CCM mutants to represent stable and unstable II values. A comparative degradation analysis was carried out under in vitro conditions using wildtype CCM, CCM mutants and two other candidate proteins: metallo-β-lactamase L1 and α -S1- casein representing stable, borderline stable/unstable, and unstable proteins as per the II predictions. The effect of temperature and a protein stabilizing agent on CCM degradation was also tested. Results: Data support the dipeptide composition-dependent protein stability/instability in wt-CCM and mutants as predicted by the II method under in vitro conditions. However, the II failed to accurately represent the stability of other tested proteins. Data indicate the influence of protein environmental factors on the autoproteolysis of proteins. Conclusion: Broader application of the II method for the prediction of protein stability under in vitro conditions is questionable as the stability of the protein may be dependent not only on the intrinsic nature of the protein but also on the conditions of the protein milieu.


Cancers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 71
Author(s):  
Sylvain D. Vallet ◽  
Coline Berthollier ◽  
Romain Salza ◽  
Laurent Muller ◽  
Sylvie Ricard-Blum

The members of the lysyl oxidase (LOX) family are amine oxidases, which initiate the covalent cross-linking of the extracellular matrix (ECM), regulate ECM stiffness, and contribute to cancer progression. The aim of this study was to build the first draft of the interactome of the five members of the LOX family in order to determine its molecular functions, the biological and signaling pathways mediating these functions, the biological processes it is involved in, and if and how it is rewired in cancer. In vitro binding assays, based on surface plasmon resonance and bio-layer interferometry, combined with queries of interaction databases and interaction datasets, were used to retrieve interaction data. The interactome was then analyzed using computational tools. We identified 31 new interactions and 14 new partners of LOXL2, including the α5β1 integrin, and built an interactome comprising 320 proteins, 5 glycosaminoglycans, and 399 interactions. This network participates in ECM organization, degradation and cross-linking, cell-ECM interactions mediated by non-integrin and integrin receptors, protein folding and chaperone activity, organ and blood vessel development, cellular response to stress, and signal transduction. We showed that this network is rewired in colorectal carcinoma, leading to a switch from ECM organization to protein folding and chaperone activity.


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