Navigation Links
Critical step traced in anthrax infection

Scientists at Harvard Medical School (HMS) have revealed details of a key step in the entry of anthrax toxin into human cells. The work, which grew out of an ongoing effort to produce a better anthrax therapeutic, shows that the protective antigen component of the bacterial toxin plays an active role in transferring the other two components of the toxin through the cell membrane.

The research, led by R. John Collier, professor of microbiology and molecular genetics at HMS, provides insight into the broader question of how proteins cross cell membranes. The findings appear in the July 29 issue of Science.

An anthrax bacterium secretes three nontoxic proteins that assemble into a toxic complex on the surface of the host cell to set off a chain of events leading to cell toxicity and death. Protective antigen (PA) is one of these proteins, and after binding to the cell, seven copies of it assemble into a specific complex that is capable of forming a pore in a cellular membrane. The pore permits the other two proteins, lethal factor (LF) and edema factor (EF), to enter the cell interior, where the factors interfere with metabolic processes, leading to death of the infected individual.

Details surrounding this process are continuing to be uncovered in Collier's lab. "Until now, we have not known whether the PA pore serves simply as a passive conduit, or alternatively, plays an active role in shepherding the unfolded LF and EF molecules through," he said. The findings show that it is the latter?the pore takes an active role in protein translocation.

The scientists demonstrated this role by investigating the channel's chemical make-up. Using a procedure known as cysteine-scanning mutagenesis, they identified the hydrophobic, or "greasy," amino acid phenylalanine in protective antigen's pore-forming domain. Seven of these amino acids project into the lumen of the pore and form a collection of greasy residues, nicknamed "the phi-clamp" by the sc
'"/>

Source:Harvard Medical School


Page: 1 2

Related biology news :

1. Critical role in programmed cell death identified
2. White Blood Cell Waste Disposal System Plays Critical Regulatory Role
3. Critical hearing gene helps send auditory messages to brain
4. Scientists seek answers on what activates deadly anthrax spores
5. Antibodies from plants protect against anthrax
6. Defensins neutralize anthrax toxin
7. US Army plans to bulk-buy anthrax
8. New antibody shows promise as cure for anthrax
9. Effective, safe anthrax vaccine can be grown in tobacco plants
10. UCSD study finds anthrax toxins also harmful to fruit flies
11. Driver of anthrax toxicity could lead to late-stage therapy
Post Your Comments:
*Name:
*Comment:
*Email:
TAG: Critical step traced anthrax infection

(Date:12/22/2014)... , Dec. 22, 2014  NXT-ID, Inc. (NASDAQ: ... authentication company focused on the growing mobile commerce market, announces ... Apollo Robbins for the 2015 International CES debut of ... Robbins will be at the NXT-ID booth January 6th ...
(Date:12/19/2014)... Dec. 18, 2014  23andMe, Inc., the leading personal genetics company, ... differences in genetic ancestry of individuals from across ... arrived more than four hundred years ago, the ... for peoples from different continents. This study illuminates how American ...
(Date:12/17/2014)... , Dec. 16, 2014 Valencell, a leader ... PerformTek biometric technology to industry leaders such as Intel, ... clinically validated, biometric wearable products. These products will be ... Las Vegas . ...
Breaking Biology News(10 mins):NXT-ID Hires Master Pickpocket and Security Consultant Apollo Robbins for Wocket Smart Wallet CES 2015 Debut 2NXT-ID Hires Master Pickpocket and Security Consultant Apollo Robbins for Wocket Smart Wallet CES 2015 Debut 3NXT-ID Hires Master Pickpocket and Security Consultant Apollo Robbins for Wocket Smart Wallet CES 2015 Debut 423andMe Study Sketches Genetic Portrait of the United States 223andMe Study Sketches Genetic Portrait of the United States 323andMe Study Sketches Genetic Portrait of the United States 4Valencell PerformTek Biometrics Power the Most Accurate Wearables at CES 2015 2
... Called BRIGHTs, the tiny probes described in the online issue ... biomarkers of disease and, when swept by an infrared laser, ... are, the probes are exquisitely engineered objects: gold nanoparticles covered ... thin shell of gold that spontaneously forms a dodecahedron. ...
... a cup of sugar and you readily comply, is your positive ... longstanding relationship? Or does it represent payment or prepayment ... need to borrow a month from now? Adrian Jaeggi, a ... research fellow at the campus,s SAGE Center for the Study of ...
... 20, 2012 Researchers at the Polytechnic Institute ... that further illuminate the emerging field of ethorobotics ... live animal counterparts. , Maurizio Porfiri, associate professor ... candidates Vladislav Kopman and Jeffrey Laut and research ...
Cached Biology News:Tiny probes shine brightly to reveal the location of targeted tissues 2Tiny probes shine brightly to reveal the location of targeted tissues 3UCSB anthropologist studies reciprocity among chimpanzees and bonobos 2UCSB anthropologist studies reciprocity among chimpanzees and bonobos 3
(Date:1/22/2015)... Controlled Substance Compliance Services (CSCS), a ... check the legal requirements around using controlled substances in ... , As their international operations expand and become increasingly ... built as a result of the first phase of ...
(Date:1/22/2015)... PALO ALTO, Calif. , Jan. 22. 2015  Varian Medical ... equipment and software, has been honored for its commitment to ... most sustainable companies. Varian is the highest ranked healthcare equipment ... ranking, announced today during the World Economic Forum at ...
(Date:12/24/2014)... and NEW YORK , Dec. 24, ... company advancing patient care in critical areas, announced the closing ... stock, and warrants to purchase up to an aggregate 3,500,000 ... per share and $.01 per warrant.  The warrants have a ...
(Date:12/24/2014)... Earlier this year in a June 24 international conference ... Cell Technology Center, LLC ( ASCTC ) focused attention on ... tissue stem cells. His title “Asymmetric Self-Renewal by Distributed ... embodied the essence of his message to congress participants. ...
Breaking Biology Technology:Global Compliance Service for Controlled Substances to Expand to China 2Varian Honored Among World's 100 Most Sustainable Corporations 2PlasmaTech Biopharmaceuticals, Inc. Announces Closing of Public Offering 2PlasmaTech Biopharmaceuticals, Inc. Announces Closing of Public Offering 3Adult Stem Cell Technology Center, LLC’s Director Sherley's Address on What’s Holding Back Regenerative Medicine Featured on Omics Group Website 2Adult Stem Cell Technology Center, LLC’s Director Sherley's Address on What’s Holding Back Regenerative Medicine Featured on Omics Group Website 3Adult Stem Cell Technology Center, LLC’s Director Sherley's Address on What’s Holding Back Regenerative Medicine Featured on Omics Group Website 4
... Multiporator / Electroporator 2510 , , , , , , , ... Protocol No. 4308 915.511 04/2002 , , ... , , Microorganism , ... Cell type , Bacteria, gram negative, , ...
... Multiporator / Electroporator 2510 , , , , , , , ... Protocol No. 4308 915.509 12/2001 , , , ... , Microorganism , Clostridium ... type , Bacteria, gram positive, , ...
... Multiporator , , , , , , , , ... Protocol No. 4308 915.031 12/1999 , , , , , ... , Cell line , CHO, Chinese hamster ... with , Rat-DPP IV (in bidistilled H 2 O), stable transfection, , ...
Cached Biology Technology:Escherichia coli C600 2Escherichia coli C600 3Clostridium botulinum 2CHO 2
...
... BCIP/NBT Chromogen system consists of ... in a single component,solution. The ... the presence of alkaline phosphatase ... minimal background noise. ,The System ...
... Covance's BCIP/NBT Chromogen system ... Tetrazolium] chromogen in a single ... reacts in the presence of ... purple staining with minimal background ...
Mouse monoclonal antibody raised against a partial recombinant VEGFB. NCBI Entrez Gene ID = VEGFB...
Biology Products: