Navigation Links
UT Southwestern researchers identify novel mechanism that helps stomach bug cause illness

DALLAS July 29, 2013 A seafood contaminant that thrives in brackish water during the summer works like a spy to infiltrate cells and quickly open communication channels to sicken the host, researchers at UT Southwestern Medical Center report.

Vibrio parahaemolyticus bacteria, which cause gastroenteritis, inject proteins called effectors into host cells. One of those effectors, VopQ, almost immediately starts to disrupt the important process of autophagy via a novel channel-forming mechanism, the scientists report in the investigation available online at the Proceedings of the National Academy of Sciences. Autophagy is the cellular housekeeping mechanism used to recycle nutrients in cells as well as to fight off pathogens. The term autophagy comes from the Greek words for self and eating. During the process, nutrients are recycled by the lysosome, an internal organelle, to produce metabolites that can be used by the cell.

"Our study identifies a bacterial effector that creates gated ion channels and reveals a novel mechanism that may regulate autophagy," said Dr. Kim Orth, professor of molecular biology and biochemistry. She is a corresponding author on the published study. The first author is Anju Sreelatha, a graduate student in Dr. Orth's laboratory.

"Disruptions of autophagic pathways are implicated in many human diseases, including neurodegenerative disease, liver disease, some cancers, and cardiomyopathy (heart muscle disease)," Ms. Sreelatha said.

She explained that ion channels are pores in the membranes of cells or of organelles within cells that allow regulated passage of small molecules or ions across membranes. Gated channels have a mechanism that opens and closes them, making these proteins potential targets for drug development.

"The identification of a channel that opens and closes and thereby affects autophagy may give us a handle by which to modulate this important process," she said, adding that the researchers found that VopQ's channel activity turned off autophagy.

"During infection, VopQ is injected into the host cell where the protein binds to a lysosomal membrane protein and forms small pores, all within minutes of infection. The resulting complex of proteins causes ions to leak and the lysosomes to de-acidify. Lacking acidification, lysosomes cannot degrade the unneeded cellular components and autophagy is disrupted," Ms. Sreelatha said.

Dr. Orth said "Bacterial pathogens have evolved a number of ways to target and manipulate host cell signaling; the ability of VopQ to form a gated ion channel and to inhibit autophagy represents a novel mechanism."

Further characterization of the mechanism by which VopQ sabotages cells to disrupt autophagy may lead to a better understanding of host-pathogen interactions as well as advance our understanding of the pathway, eventually leading to new treatments for diseases in which autophagy has gone awry, they noted.


Contact: Deborah Wormser
UT Southwestern Medical Center

Related biology news :

1. UT Southwestern scientists make mouse model of human cancer, demonstrate cure
2. Mesquite trees displacing Southwestern grasslands
3. Researchers uncover cellular mechanisms for attention in the brain
4. Notre Dame researchers develop system that uses a big data approach to personalized healthcare
5. U of M researchers unveil nations first porcine virus rapid detection test
6. Researchers reveal the clearest new pictures of immune cells
7. Researchers describe potential for MERS coronavirus to spread internationally
8. U of M researchers identify new functions for autoimmune disease risk gene
9. Solving DNA puzzles is overwhelming computer systems, researchers warn
10. Antiviral enzyme contributes to several forms of cancer, University of Minnesota researchers say
11. Carnegie Mellon researchers develop artificial cells to study molecular crowding and gene expression
Post Your Comments:
(Date:11/26/2015)... 26, 2015 Research and Markets ( ... Fingerprint Sensors - Technology and Patent Infringement Risk Analysis" ... --> --> Fingerprint sensors using capacitive ... The fingerprint sensor vendor Idex forecasts an increase of ... mobile devices and of the fingerprint sensor market between ...
(Date:11/19/2015)... MOUNTAIN VIEW, Calif. , Nov. 19, 2015 /PRNewswire/ ... authentication market, Frost & Sullivan recognizes BIO-key with the ... Strategy Leadership. Each year, Frost & Sullivan presents this ... comprehensive product line catering to the needs of the ... which the product line meets and expands on customer ...
(Date:11/18/2015)... new scientific discoveries deepen our understanding of how cancer ... challenges in better using that knowledge to guide treatment ... children continue to survive pediatric cancer, that counseling may ... John M. Maris, M.D ., a pediatric oncologist ... --> John M. Maris, M.D ., ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... LOS ANGELES and HOLLISTON, Mass. ... Regenerative Technology, Inc. (Nasdaq: HART ), a biotechnology ... announced that CEO Jim McGorry will present ... Tuesday, December 1, 2015 at 2:30 p.m. PT. The ... (link below) for 30 days. Management will also be ...
(Date:11/25/2015)... ... November 25, 2015 , ... A long-standing ... Aerospace Professionals (OPBAP) has been formalized with the signing of a Memorandum of ... with OPBAP leaders Capt. Karl Minter and Capt. Albert Glenn Tuesday, November 24, ...
(Date:11/25/2015)... (PRWEB) , ... November 25, 2015 , ... ... company uBiome, were featured on AngelList early in their initial angel funding process. ... AngelList syndicate for individuals looking to make early stage investments in the microbiome ...
(Date:11/24/2015)... , Nov. 24, 2015 Cepheid (NASDAQ: ... speaking at the following conference, and invited investors to ... NY      Tuesday, December 1, 2015 at 11.00 ... NY      Tuesday, December 1, 2015 at 11.00 ... Conference, New York, NY      Tuesday, ...
Breaking Biology Technology: