scholarly journals Bacteria Use Structural Imperfect Mimicry To Hijack The Host Interactome

Author(s):  
Natalia Sanchez de Groot ◽  
Marc Torrent Burgas

ABSTRACTBacteria use protein-protein interactions to infect their hosts and hijack fundamental pathways, which ensures their survival and proliferation. Hence, the infectious capacity of the pathogen is closely related to its ability to interact with host proteins. Here, we show that hubs in the host-pathogen interactome are isolated in the pathogen network by adapting the geometry of the interacting interfaces. An imperfect mimicry of the eukaryotic interfaces allows pathogen proteins to actively bind to the host’s target while preventing deleterious effects on the pathogen interactome. Understanding how bacteria recognize eukaryotic proteins may pave the way for the rational design of new antibiotic molecules.

2020 ◽  
Vol 16 (12) ◽  
pp. e1008395
Author(s):  
Natalia Sanchez de Groot ◽  
Marc Torrent Burgas

Bacteria use protein-protein interactions to infect their hosts and hijack fundamental pathways, which ensures their survival and proliferation. Hence, the infectious capacity of the pathogen is closely related to its ability to interact with host proteins. Here, we show that hubs in the host-pathogen interactome are isolated in the pathogen network by adapting the geometry of the interacting interfaces. An imperfect mimicry of the eukaryotic interfaces allows pathogen proteins to actively bind to the host’s target while preventing deleterious effects on the pathogen interactome. Understanding how bacteria recognize eukaryotic proteins may pave the way for the rational design of new antibiotic molecules.


2019 ◽  
Author(s):  
Macy G. Olson ◽  
Ray E. Widner ◽  
Lisa M. Jorgenson ◽  
Alyssa Lawrence ◽  
Dragana Lagundzin ◽  
...  

AbstractAs an obligate intracellular pathogenic bacterium,C. trachomatisdevelops within a membrane-bound vacuole, termed the inclusion. The inclusion membrane is modified by chlamydial inclusion membrane proteins (Incs), which act as the mediators of host-pathogen interactions. Anin vivounderstanding of Inc-Inc and Inc-eukaryotic protein interactions and how these contribute to overall host-chlamydial interactions at this unique membrane is lacking. Previous bacterial two-hybrid studies established that certain Incs have the propensity to bind other Incs while others have limited Inc-Inc interactions. We hypothesize some Incs organize the inclusion membrane whereas other Incs bind eukaryotic proteins to promote chlamydial-host interactions. To test this hypothesis, we used the ascorbate peroxidase proximity labeling system (APEX2), which labels proximal proteins with biotinin vivo, and chose to analyze Inc proteins with varying Inc-binding propensities. We inducibly expressed these Incs fused to APEX2 inChlamydia trachomatisL2, verified their localization and labeling activities by transmission electron microscopy, and used affinity purification-mass spectrometry to identify biotinylated proteins. To analyze our mass spectrometry results for statistical significance, we used Significance Analysis of INTeractome (SAINT), which demonstrated that our Inc-APEX2 constructs labeled Inc proteins as well as known and previously unreported eukaryotic proteins that localize to the inclusion. Our results broadly support two types of Inc interactions: Inc-Inc versus Inc-host. One eukaryotic protein, LRRFIP1 (LRRF1) was found in all of our Inc-APEX2 datasets, which is consistent with previously published AP-MS datasets. For the first time, we demonstrate by confocal and super-resolution microscopy that endogenous LRRF1 localizes to the chlamydial inclusion. We also used bacterial two-hybrid studies and pulldown assays to determine if LRRF1 was identified as a true interacting protein or was proximal to our Inc-APEX2 constructs. Combined, our data highlight the utility of APEX2 to capture the complexin vivoprotein-protein interactions at the chlamydial inclusion.Author summaryMany intracellular bacteria, including the obligate intracellular pathogenChlamydia trachomatis, grow within a membrane-bound “bacteria containing vacuole” (BCV) that, in most cases, prevents association with the lysosome. Secreted cytosolic effectors modulate host activity, but an understanding of the host-pathogen interactions that occur at the BCV membrane is limited by the difficulty in purifying membrane fractions from infected host cells. Here, we used the ascorbate peroxidase proximity labeling system (APEX2), which labels proximal proteins with biotinin vivo, to study the interactions that occur at the chlamydial vacuolar, or inclusion, membrane. The inclusion membrane is modified by chlamydial type III secreted inclusion membrane proteins (Incs), which act as the mediators of host-pathogen interactions. Our results broadly support two types of Inc interactions: Inc-Inc versus Inc-host. Our data highlight the utility of APEX2 to capture the complex protein-protein interactions at a membrane sitein vivoin the context of infection.


F1000Research ◽  
2015 ◽  
Vol 3 ◽  
pp. 251 ◽  
Author(s):  
Sandeep Chakraborty ◽  
Basuthkar J. Rao ◽  
Bjarni Asgeirsson ◽  
Abhaya M. Dandekar

Ebola, considered till recently as a rare and endemic disease, has dramatically transformed into a potentially global humanitarian crisis. The genome of Ebola, a member of the Filoviridae family, encodes seven proteins. Based on the recently implemented software (PAGAL) for analyzing the hydrophobicity and amphipathicity properties of alpha helices (AH) in proteins, we characterize the helices in the Ebola proteome. We demonstrate that AHs with characteristically unique features are involved in critical interactions with the host proteins. For example, the Ebola virus membrane fusion subunit, GP2, from the envelope glycoprotein ectodomain has an AH with a large hydrophobic moment. The neutralizing antibody (KZ52) derived from a human survivor of the 1995 Kikwit outbreak recognizes a protein epitope on this AH, emphasizing the critical nature of this secondary structure in the virulence of the Ebola virus. Our method ensures a comprehensive list of such `hotspots'. These helices probably are or can be the target of molecules designed to inhibit AH mediated protein-protein interactions. Further, by comparing the AHs in proteins of the related Marburg viruses, we are able to elicit subtle changes in the proteins that might render them ineffective to previously successful drugs. Such differences are difficult to identify by a simple sequence or structural alignment. Thus, analyzing AHs in the small Ebola proteome can aid rational design aimed at countering the `largest Ebola epidemic, affecting multiple countries in West Africa' (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/index.html).


2019 ◽  
Vol 87 (11) ◽  
Author(s):  
Macy G. Olson ◽  
Ray E. Widner ◽  
Lisa M. Jorgenson ◽  
Alyssa Lawrence ◽  
Dragana Lagundzin ◽  
...  

ABSTRACT Many intracellular bacteria, including the obligate intracellular pathogen Chlamydia trachomatis, grow within a membrane-bound bacterium-containing vacuole (BCV). Secreted cytosolic effectors modulate host activity, but an understanding of the host-pathogen interactions that occur at the BCV membrane is limited by the difficulty in purifying membrane fractions from infected host cells. We used the ascorbate peroxidase (APEX2) proximity labeling system, which labels proximal proteins with biotin in vivo, to study the protein-protein interactions that occur at the chlamydial vacuolar, or inclusion, membrane. An in vivo understanding of the secreted chlamydial inclusion membrane protein (Inc) interactions (e.g., Inc-Inc and Inc-eukaryotic protein) and how these contribute to overall host-chlamydia interactions at this unique membrane is lacking. We hypothesize some Incs organize the inclusion membrane, whereas other Incs bind eukaryotic proteins to promote chlamydia-host interactions. To study this, Incs fused to APEX2 were expressed in C. trachomatis L2. Affinity purification-mass spectrometry (AP-MS) identified biotinylated proteins, which were analyzed for statistical significance using significance analysis of the interactome (SAINT). Broadly supporting both Inc-Inc and Inc-host interactions, our Inc-APEX2 constructs labeled Incs as well as known and previously unreported eukaryotic proteins localizing to the inclusion. We demonstrate, using bacterial two-hybrid and coimmunoprecipitation assays, that endogenous LRRFIP1 (LRRF1) is recruited to the inclusion by the Inc CT226. We further demonstrate interactions between CT226 and the Incs used in our study to reveal a model for inclusion membrane organization. Combined, our data highlight the utility of APEX2 to capture the complex in vivo protein-protein interactions at the chlamydial inclusion.


F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 251 ◽  
Author(s):  
Sandeep Chakraborty ◽  
Basuthkar J. Rao ◽  
Bjarni Asgeirsson ◽  
Abhaya M. Dandekar

Ebola, considered till recently as a rare and endemic disease, has dramatically transformed into a potentially global humanitarian crisis. The genome of Ebola, a member of the Filoviridae family, encodes seven proteins. Based on the recently implemented software (PAGAL) for analyzing the hydrophobicity and amphipathicity properties of alpha helices (AH) in proteins, we characterize the helices in the Ebola proteome. We demonstrate that AHs with characteristically unique features are involved in critical interactions with the host proteins. For example, the Ebola virus membrane fusion subunit, GP2, from the envelope glycoprotein ectodomain has an AH with a large hydrophobic moment. The ability of this AH to bind to other host proteins is disrupted by a neutralizing antibody derived from a human survivor of the 1995 Kikwit outbreak, emphasizing the critical nature of this secondary structure in the virulence of the Ebola virus. Our method ensures a comprehensive list of such `hotspots'. These helices probably are or can be the target of molecules designed to inhibit AH mediated protein-protein interactions. Further, by comparing the AHs in proteins of the related Marburg viruses, we are able to elicit subtle changes in the proteins that might render them ineffective to previously successful drugs. Such differences are difficult to identify by a simple sequence or structural alignment. Thus, analyzing AHs in the small Ebola proteome can aid rational design aimed at countering the `largest Ebola epidemic, affecting multiple countries in West Africa' (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/index.html).


F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 251
Author(s):  
Sandeep Chakraborty ◽  
Basuthkar J. Rao ◽  
Bjarni Asgeirsson ◽  
Abhaya M. Dandekar

Ebola, considered till recently as a rare and endemic disease, has dramatically transformed into a potentially global humanitarian crisis. The genome of Ebola, a member of the Filoviridae family, encodes seven proteins. Based on the recently implemented software (PAGAL) for analyzing the hydrophobicity and amphipathicity properties of alpha helices (AH) in proteins, we characterize the helices in the Ebola proteome. We demonstrate that AHs with characteristically unique features are involved in critical interactions with the host proteins. For example, the Ebola virus membrane fusion subunit, GP2, from the envelope glycoprotein ectodomain has an AH with a large hydrophobic moment. The neutralizing antibody (KZ52) derived from a human survivor of the 1995 Kikwit outbreak recognizes a protein epitope on this AH, emphasizing the critical nature of this secondary structure in the virulence of the Ebola virus. Our method ensures a comprehensive list of such `hotspots'. These helices probably are or can be the target of molecules designed to inhibit AH mediated protein-protein interactions. Further, by comparing the AHs in proteins of the related Marburg viruses, we are able to elicit subtle changes in the proteins that might render them ineffective to previously successful drugs. Such differences are difficult to identify by a simple sequence or structural alignment. Thus, analyzing AHs in the small Ebola proteome can aid rational design aimed at countering the `largest Ebola epidemic, affecting multiple countries in West Africa' (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/index.html).


2020 ◽  
Vol 85 (16) ◽  
pp. 10552-10560
Author(s):  
Peng Sang ◽  
Yan Shi ◽  
Pirada Higbee ◽  
Minghui Wang ◽  
Sami Abdulkadir ◽  
...  

2020 ◽  
Author(s):  
Ramesh K. Jha ◽  
Allison Yankey ◽  
Kalifa Shabazz ◽  
Leslie Naranjo ◽  
Nileena Velappan ◽  
...  

ABSTRACTWhile natural protein-protein interactions have evolved to be induced by complex stimuli, rational design of interactions that can be switched-on-demand still remain challenging in the protein design world. Here, we demonstrate a computationally redesigned natural interface for improved binding affinity could further be mutated to adopt a pH switchable interaction. The redesigned interface of Protein G-IgG Fc domain, when incorporated with histidine and glutamic acid on Protein G (PrG-EHHE), showed a switch in binding affinity by 50-fold when pH was altered from mild acidic to mild basic. The wild type (WT) interface only showed negligible switch. The overall binding affinity at mild acidic pH for PrG-EHHE outperformed the WT PrG interaction. The new reagent PrG-EHHE will be revolutionary in IgG purification since the traditional method of using an extreme acidic pH for elution can be circumvented.Abstract Figure


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kais Ghedira ◽  
Yosr Hamdi ◽  
Abir El Béji ◽  
Houcemeddine Othman

Host-pathogen molecular cross-talks are critical in determining the pathophysiology of a specific infection. Most of these cross-talks are mediated via protein-protein interactions between the host and the pathogen (HP-PPI). Thus, it is essential to know how some pathogens interact with their hosts to understand the mechanism of infections. Malaria is a life-threatening disease caused by an obligate intracellular parasite belonging to the Plasmodium genus, of which P. falciparum is the most prevalent. Several previous studies predicted human-plasmodium protein-protein interactions using computational methods have demonstrated their utility, accuracy, and efficiency to identify the interacting partners and therefore complementing experimental efforts to characterize host-pathogen interaction networks. To predict potential putative HP-PPIs, we use an integrative computational approach based on the combination of multiple OMICS-based methods including human red blood cells (RBC) and Plasmodium falciparum 3D7 strain expressed proteins, domain-domain based PPI, similarity of gene ontology terms, structure similarity method homology identification, and machine learning prediction. Our results reported a set of 716 protein interactions involving 302 human proteins and 130 Plasmodium proteins. This work provides a list of potential human-Plasmodium interacting proteins. These findings will contribute to better understand the mechanisms underlying the molecular determinism of malaria disease and potentially to identify candidate pharmacological targets.


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