scholarly journals Host cell binding of the flagellar tip protein ofCampylobacter jejuni

2017 ◽  
Vol 19 (6) ◽  
pp. e12714 ◽  
Author(s):  
Claudia M. Freitag ◽  
Karin Strijbis ◽  
Jos P.M. van Putten
Keyword(s):  
Host Cell ◽  
Cell Binding ◽  
Ofcampylobacter Jejuni

scholarly journals The Campylobacter jejuni CiaD effector co-opts the host cell protein IQGAP1 to promote cell entry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nicholas M. Negretti ◽  
Christopher R. Gourley ◽  
Prabhat K. Talukdar ◽  
Geremy Clair ◽  
Courtney M. Klappenbach ◽  
...  
Keyword(s):  
Host Cell ◽  
Campylobacter Jejuni ◽  
Foodborne Pathogen ◽  
Small Gtpase ◽  
Host Cells ◽  
Cell Protein ◽  
Host Cell Protein ◽  
Cell Binding ◽  
Actin Reorganization ◽  
Cell Cytosol

AbstractCampylobacter jejuni is a foodborne pathogen that binds to and invades the epithelial cells lining the human intestinal tract. Maximal invasion of host cells by C. jejuni requires cell binding as well as delivery of the Cia proteins (Campylobacter invasion antigens) to the host cell cytosol via the flagellum. Here, we show that CiaD binds to the host cell protein IQGAP1 (a Ras GTPase-activating-like protein), thus displacing RacGAP1 from the IQGAP1 complex. This, in turn, leads to the unconstrained activity of the small GTPase Rac1, which is known to have roles in actin reorganization and internalization of C. jejuni. Our results represent the identification of a host cell protein targeted by a flagellar secreted effector protein and demonstrate that C. jejuni-stimulated Rac signaling is dependent on IQGAP1.

scholarly journals Molecular Dissection of the Campylobacter jejuni CadF and FlpA Virulence Proteins in Binding to Host Cell Fibronectin

2020 ◽  
Vol 8 (3) ◽  
pp. 389 ◽  
Author(s):  
Prabhat K. Talukdar ◽  
Nicholas M. Negretti ◽  
Kyrah L. Turner ◽  
Michael E. Konkel
Keyword(s):  
Host Cell ◽  
Campylobacter Jejuni ◽  
Mapk Signaling ◽  
Effector Proteins ◽  
Host Cells ◽  
Target Cells ◽  
Cell Binding ◽  
Virulence Proteins ◽  
Host Target ◽  
Cell Signaling Pathways

Campylobacter jejuni, a zoonotic pathogen that frequently colonizes poultry, possesses two Microbial Surface Components Recognizing Adhesive Matrix Molecule(s) (MSCRAMMs) termed CadF and FlpA that bind to the glycoprotein fibronectin (FN). Previous to this study, it was not known whether the CadF and FlpA proteins were functionally redundant or if both were required to potentiate host cell binding and signaling processes. We addressed these questions by generating a complete repertoire of cadF and flpA mutants and complemented isolates, and performing multiple phenotypic assays. Both CadF and FlpA were found to be necessary for the maximal binding of C. jejuni to FN and to host cells. In addition, both CadF and FlpA are required for the delivery of the C. jejuni Cia effector proteins into the cytosol of host target cells, which in turn activates the MAPK signaling pathway (Erk 1/2) that is required for the C. jejuni invasion of host cells. These data demonstrate the non-redundant and bi-functional nature of these two C. jejuni FN-binding proteins. Taken together, the C. jejuni CadF and FlpA adhesins facilitate the binding of C. jejuni to the host cells, permit delivery of effector proteins into the cytosol of a host target cell, and aid in the rewiring of host cell signaling pathways to alter host cell behavior.

scholarly journals Recruitment of Mammalian Cell Fibronectin to the Surface of Chlamydia trachomatis

2002 ◽  
Vol 70 (7) ◽  
pp. 3935-3938 ◽  
Author(s):  
Betsy J. Kleba ◽  
Erin Banta ◽  
Erika A. Lindquist ◽  
Richard S. Stephens
Keyword(s):  
Chlamydia Trachomatis ◽  
Heparan Sulfate ◽  
Host Cell ◽  
Mammalian Cell ◽  
Pathogenic Bacteria ◽  
Cell Binding ◽  
Cell Functions ◽  
Wide Range

ABSTRACT Pathogenic bacteria exploit the presence of various host cell molecules in order to colonize new tissues. Fibronectin is involved in a wide range of cell functions in vivo, and staphylococci, streptococci, and gonococci have evolved mechanisms to utilize this glycoprotein to mediate host cell binding. We show that elementary bodies (EB) from two biovars of Chlamydia trachomatis recruit fibronectin to their surfaces upon lysis of the host cell. We also demonstrate that a heparan sulfate lyase-sensitive molecule on chlamydial EB is responsible for binding at least a portion of this fibronectin.

scholarly journals Adaptation of the Lyme disease spirochaete to the mammalian host environment results in enhanced glycosaminoglycan and host cell binding

2003 ◽  
Vol 47 (5) ◽  
pp. 1433-1444 ◽  
Author(s):  
Nikhat Parveen ◽  
Melissa Caimano ◽  
Justin D. Radolf ◽  
John M. Leong
Keyword(s):  
Lyme Disease ◽  
Host Cell ◽  
Mammalian Host ◽  
Cell Binding ◽  
Host Environment

scholarly journals HtrA chaperone activity contributes to host cell binding in Campylobacter jejuni

Gut Pathogens ◽  
2011 ◽  
Vol 3 (1) ◽  
pp. 13 ◽  
Author(s):  
Kristoffer T Bæk ◽  
Christina S Vegge ◽  
Lone Brøndsted
Keyword(s):  
Host Cell ◽  
Campylobacter Jejuni ◽  
Chaperone Activity ◽  
Cell Binding

scholarly journals Not a Simple Tether: Binding of Toxoplasma gondii AMA1 to RON2 during Invasion Protects AMA1 from Rhomboid-Mediated Cleavage and Leads to Dephosphorylation of Its Cytosolic Tail

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
Shruthi Krishnamurthy ◽  
Bin Deng ◽  
Roxana del Rio ◽  
Kerry R. Buchholz ◽  
Moritz Treeck ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Host Cell ◽  
Cell Invasion ◽  
Transmembrane Domain ◽  
Critical Role ◽  
Host Cells ◽  
Receptor Protein ◽  
Host Cell Invasion ◽  
Cell Binding ◽  
Apicomplexan Parasites

ABSTRACT Apical membrane antigen 1 (AMA1) is a receptor protein on the surface of Toxoplasma gondii that plays a critical role in host cell invasion. The ligand to which T . gondii AMA1 (TgAMA1) binds, TgRON2, is secreted into the host cell membrane by the parasite during the early stages of invasion. The TgAMA1-TgRON2 complex forms the core of the “moving junction,” a ring-shaped zone of tight contact between the parasite and host cell membranes, through which the parasite pushes itself during invasion. Paradoxically, the parasite also expresses rhomboid proteases that constitutively cleave the TgAMA1 transmembrane domain. How can TgAMA1 function effectively in host cell binding if its extracellular domain is constantly shed from the parasite surface? We show here that when TgAMA1 binds the domain 3 (D3) peptide of TgRON2, its susceptibility to cleavage by rhomboid protease(s) is greatly reduced. This likely serves to maintain parasite-host cell binding at the moving junction, a hypothesis supported by data showing that parasites expressing a hypercleavable version of TgAMA1 invade less efficiently than wild-type parasites do. Treatment of parasites with the D3 peptide was also found to reduce phosphorylation of S527 on the cytoplasmic tail of TgAMA1, and parasites expressing a phosphomimetic S527D allele of TgAMA1 showed an invasion defect. Taken together, these data suggest that TgAMA1-TgRON2 interaction at the moving junction protects TgAMA1 molecules that are actively engaged in host cell penetration from rhomboid-mediated cleavage and generates an outside-in signal that leads to dephosphorylation of the TgAMA1 cytosolic tail. Both of these effects are required for maximally efficient host cell invasion. IMPORTANCE Nearly one-third of the world’s population is infected with the protozoan parasite Toxoplasma gondii , which causes life-threatening disease in neonates and immunocompromised individuals. T. gondii is a member of the phylum Apicomplexa, which includes many other parasites of veterinary and medical importance, such as those that cause coccidiosis, babesiosis, and malaria. Apicomplexan parasites grow within their hosts through repeated cycles of host cell invasion, parasite replication, and host cell lysis. Parasites that cannot invade host cells cannot survive or cause disease. AMA1 is a highly conserved protein on the surface of apicomplexan parasites that is known to be important for invasion, and the work presented here reveals new and unexpected insights into AMA1 function. A more complete understanding of the role of AMA1 in invasion may ultimately contribute to the development of new chemotherapeutics designed to disrupt AMA1 function and invasion-related signaling in this important group of human pathogens.

scholarly journals Crystal structure of the outer membrane protein OmpU fromVibrio choleraeat 2.2 Å resolution

2018 ◽  
Vol 74 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Huanyu Li ◽  
Weijiao Zhang ◽  
Changjiang Dong
Keyword(s):  
Crystal Structure ◽  
Membrane Protein ◽  
Host Cell ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Severe Disease ◽  
Cell Interaction ◽  
Cell Binding ◽  
Important Virulence Factor ◽  
Host Cell Interaction

Vibrio choleraecauses a severe disease that kills thousands of people annually. The outer membrane protein OmpU is the most abundant outer membrane protein inV. cholerae, and has been identified as an important virulence factor that is involved in host-cell interaction and recognition, as well as being critical for the survival of the pathogenicV. choleraein the host body and in harsh environments. The mechanism of these processes is not well understood owing to a lack of the structure ofV. choleraeOmpU. Here, the crystal structure of theV. choleraeOmpU trimer is reported to a resolution of 2.2 Å. The protomer forms a 16-β-stranded barrel with a noncanonical N-terminal coil located in the lumen of the barrel that consists of residues Gly32–Ser42 and is observed to participate in forming the second gate in the pore. By mapping the published functional data onto the OmpU structure, the OmpU structure reinforces the notion that the long extracellular loop L4 with a β-hairpin-like motif may be critical for host-cell binding and invasion, while L3, L4 and L8 are crucially implicated in phage recognition byV. cholerae.

Atomic evidence that modification of H-bonds established with amino acids critical for host-cell binding induces sterile immunity against malaria

2010 ◽  
Vol 394 (3) ◽  
pp. 529-535 ◽  
Author(s):  
Manuel E. Patarroyo ◽  
Gladys Cifuentes ◽  
Camilo Piraján ◽  
Armando Moreno-Vranich ◽  
Magnolia Vanegas
Keyword(s):  
Amino Acids ◽  
Host Cell ◽  
Cell Binding
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