N-Terminal Region of Vibrio parahemolyticus Thermostable Direct Hemolysin Regulates the Membrane-Damaging Action of the Toxin

Biochemistry ◽  
2019 ◽  
Vol 59 (4) ◽  
pp. 605-614
Author(s):  
Nidhi Kundu ◽  
Pratima Verma ◽  
Anil Kumar ◽  
Vinica Dhar ◽  
Somnath Dutta ◽  
...  
Keyword(s):  
Terminal Region ◽  
Vibrio Parahemolyticus ◽  
Thermostable Direct Hemolysin

Disulphide bond restrains the C-terminal region of thermostable direct hemolysin during folding to promote oligomerization

2017 ◽  
Vol 474 (2) ◽  
pp. 317-331 ◽  
Author(s):  
Nidhi Kundu ◽  
Swapnil Tichkule ◽  
Shashi Bhushan Pandit ◽  
Kausik Chattopadhyay
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Bond Formation ◽  
Terminal Region ◽  
Water Soluble ◽  
Disulphide Bond ◽  
Target Cells ◽  
Disulphide Bond Formation ◽  
Oligomeric Assembly ◽  
Thermostable Direct Hemolysin ◽  
Tetrameric Assembly

Pore-forming toxins (PFTs) are typically produced as water-soluble monomers, which upon interacting with target cells assemble into transmembrane oligomeric pores. Vibrio parahaemolyticus thermostable direct hemolysin (TDH) is an atypical PFT that exists as a tetramer in solution, prior to membrane binding. The TDH structure highlights a core β-sandwich domain similar to those found in the eukaryotic actinoporin family of PFTs. However, the TDH structure harbors an extended C-terminal region (CTR) that is not documented in the actinoporins. This CTR remains tethered to the β-sandwich domain through an intra-molecular disulphide bond. Part of the CTR is positioned at the inter-protomer interface in the TDH tetramer. Here we show that the truncation, as well as mutation, of the CTR compromise tetrameric assembly, and the membrane-damaging activity of TDH. Our study also reveals that intra-protomer disulphide bond formation during the folding/assembly process of TDH restrains the CTR to mediate its participation in the formation of inter-protomer contact, thus facilitating TDH oligomerization. However, once tetramerization is achieved, disruption of the disulphide bond does not affect oligomeric assembly. Our study provides critical insights regarding the regulation of the oligomerization mechanism of TDH, which has not been previously documented in the PFT family.

Antibodies against the COOH-terminal region of E. coli ClpP protease in patients with primary biliary cirrhosis

2000 ◽  
Vol 33 (4) ◽  
pp. 528-536 ◽  
Author(s):  
Isabel Mayo ◽  
Paz Arizti ◽  
Albert Pares ◽  
Joaquin Oliva ◽  
Rita Alvarez Doforno ◽  
...  
Keyword(s):  
Primary Biliary Cirrhosis ◽  
Terminal Region ◽  
Biliary Cirrhosis ◽  
E Coli

Human Cardiac Ryanodine Receptor: Preparation, Crystallization and Preliminary X-ray Analysis of the N-terminal Region

2013 ◽  
Vol 20 (11) ◽  
pp. 1211-1216 ◽  
Author(s):  
L’ubomír Borko ◽  
Július Kostan ◽  
Alexandra Zahradníkova ◽  
Vladimír Pevala ◽  
Juraj Gasperík ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
Terminal Region ◽  
X Ray ◽  
Cardiac Ryanodine Receptor

scholarly journals Mutation of the N-Terminal Region of Chikungunya Virus Capsid Protein: Implications for Vaccine Design

mBio ◽  
2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Adam Taylor ◽  
Xiang Liu ◽  
Ali Zaid ◽  
Lucas Y. H. Goh ◽  
Jody Hobson-Peters ◽  
...  
Keyword(s):  
Host Cell ◽  
Capsid Protein ◽  
Chikungunya Virus ◽  
Fluorescent Protein ◽  
Nuclear Translocation ◽  
Vaccine Design ◽  
Terminal Region ◽  
Site Directed Mutagenesis ◽  
Nucleolar Localization ◽  
Localization Sequence

ABSTRACTMosquito-transmitted chikungunya virus (CHIKV) is an arthritogenic alphavirus of theTogaviridaefamily responsible for frequent outbreaks of arthritic disease in humans. Capsid protein, a structural protein encoded by the CHIKV RNA genome, is able to translocate to the host cell nucleolus. In encephalitic alphaviruses, nuclear translocation induces host cell transcriptional shutoff; however, the role of capsid protein nucleolar localization in arthritogenic alphaviruses remains unclear. Using recombinant enhanced green fluorescent protein (EGFP)-tagged expression constructs and CHIKV infectious clones, we describe a nucleolar localization sequence (NoLS) in the N-terminal region of capsid protein, previously uncharacterized in CHIKV. Mutation of the NoLS by site-directed mutagenesis reduced efficiency of nuclear import of CHIKV capsid protein. In the virus, mutation of the capsid protein NoLS (CHIKV-NoLS) attenuated replication in mammalian and mosquito cells, producing a small-plaque phenotype. Attenuation of CHIKV-NoLS is likely due to disruption of the viral replication cycle downstream of viral RNA synthesis. In mice, CHIKV-NoLS infection caused no disease signs compared to wild-type CHIKV (CHIKV-WT)-infected mice; lack of disease signs correlated with significantly reduced viremia and decreased expression of proinflammatory factors. Mice immunized with CHIKV-NoLS, challenged with CHIKV-WT at 30 days postimmunization, develop no disease signs and no detectable viremia. Serum from CHIKV-NoLS-immunized mice is able to efficiently neutralize CHIKV infectionin vitro. Additionally, CHIKV-NoLS-immunized mice challenged with the related alphavirus Ross River virus showed reduced early and peak viremia postchallenge, indicating a cross-protective effect. The high degree of CHIKV-NoLS attenuation may improve CHIKV antiviral and rational vaccine design.IMPORTANCECHIKV is a mosquito-borne pathogen capable of causing explosive epidemics of incapacitating joint pain affecting millions of people. After a series of major outbreaks over the last 10 years, CHIKV and its mosquito vectors have been able to expand their range extensively, now making CHIKV a human pathogen of global importance. With no licensed vaccine or antiviral therapy for the treatment of CHIKV disease, there is a growing need to understand the molecular determinants of viral pathogenesis. These studies identify a previously uncharacterized nucleolar localization sequence (NoLS) in CHIKV capsid protein, begin a functional analysis of site-directed mutants of the capsid protein NoLS, and examine the effect of the NoLS mutation on CHIKV pathogenesisin vivoand its potential to influence CHIKV vaccine design. A better understanding of the pathobiology of CHIKV disease will aid the development of effective therapeutic strategies.

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