Navigation Links
Starting signal for antiviral defense
Date:5/7/2014

In human cells, DNA occurs only in the cell nucleus as the carrier of genetic information. In order to protect it, specialized proteins regularly scan the individual strands for defects, and repair them. One example of this is the protein Rad50, a DNA sensor that binds to DNA and detects defective sites. A team of scientists headed by Prof. Jrgen Ruland of the TUM together with colleagues from the LMU have now discovered another important task performed by Rad50.

There is normally no DNA in the cytoplasm surrounding the cell nucleus. However, if any does turn up there, it is frequently foreign DNA from a virus, for instance, that has infected the cell. Just like humans, some types of viruses use DNA to carry their genetic information. Thus the innate immune system has developed alarm mechanisms to detect foreign DNA in cytoplasm quickly and effectively, and activate the immune system by producing messenger substances.

However, it remains largely unclear just how this activation process occurs in the cytoplasm. In their study, lead author Dr. Susanne Roth and her colleagues have now shown that the DNA sensor Rad50 from the cell nucleus is also an important trigger for antiviral defense. "It is very surprising even for us that Rad50, which specializes in DNA in the cell nucleus, also detects foreign viral DNA and acts as a connecting link for the corresponding immune response", says Prof. Jrgen Ruland, explaining the significance of the findings.

One protein - two functions

In their experiments, the participating scientists infected immune cells with a virus that introduced its DNA into the cytoplasm. They were able to show that Rad50 bound to the viral DNA in the cytoplasm, even though it normally docks onto damaged DNA in the cell nucleus. A crucial factor was that Rad50 interacted with a specific signal protein (CARD9) of the immune system at the same time, forming a complex. The researchers succeeded in demonstrating this connection in cells for the first time.

The formation of the complex activated a signal transduction pathway in the cell which ended with production of the messenger substance interleukin 1β. This vital "global player" of the immune system is responsible for the onset of fever as a defense mechanism against pathogens, but also has a role in autoimmune diseases, such as rheumatoid arthritis.

In order to confirm their results, the researchers then used cells containing either no Rad50 or no CARD9, and again introduced DNA into their cytoplasm. Both cell types then produced far less interleukin 1β, as the Rad50-CARD9 complex could not be formed in order to activate the alarm system.

"Too much or too little of IL-1β can lead to a defective immune response or chronic disease, so its production must be strictly regulated by the body", explains Jrgen Ruland. "Now that we know Rad50 and CARD9 are important triggers for the alarm system and IL-1β production, we can gain a better understanding of many immune responses and develop strategies to influence them therapeutically."


'/>"/>

Contact: Vera Siegler
vera.siegler@tum.de
49-892-892-2731
Technische Universitaet Muenchen
Source:Eurekalert

Related biology news :

1. Starting a family does not encourage parents to eat healthier
2. ERC starting grant for Friederike Range
3. Unexpected discovery reveals a new mechanism for how the cerebellum extracts signal from noise
4. To drive infections, a hijacking virus mimics a cells signaling system
5. Tiny electrical sensors could signal faster MRSA diagnosis
6. Protein signal is crucial for accurate control of insect size
7. Deterring signals: Tobacco plants advertise their defensive readiness to attacking leafhoppers
8. Bacterium signals plant to open up and let friends in
9. Scientists tie DNA repair to key cell signaling network
10. Ion selectivity in neuronal signaling channels evolved twice in animals
11. Long-distance distress signal from periphery of injured nerve cells begins with locally made protein
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/18/2018)... PARK, Kan. (PRWEB) , ... October 18, 2018 ... ... to 23andMe, Inc., a leader among services that offer direct-to-consumer DNA Testing for ... Testing seems to be everywhere. The reasons are many: some people want to ...
(Date:10/17/2018)... ... October 17, 2018 , ... Maintenance of ... patients, say 65 percent of physicians surveyed by MDLinx, a medical news, information, ... of medical specialties revealed that many physicians are frustrated with the mandated MOC ...
(Date:10/16/2018)... , ... October 15, 2018 , ... ... chain operations solutions for highly regulated industries, is a silver sponsor and exhibitor ... Diego, California. , The Biomanufacturing World Summit brings together the “who’s ...
Breaking Biology News(10 mins):
(Date:10/5/2018)... ... October 04, 2018 , ... Power ... a Spine Technology Award from Orthopedics This Week during the 2018 National Association ... T Handle is a surgical instrument that delivers operating room efficiencies through increased ...
(Date:10/5/2018)... , ... October 04, 2018 , ... ... brand identity and website that elevates the company’s brand identity and better reflects ... company offers a broader range of engineering expertise and related support services to ...
(Date:10/2/2018)... ... October 02, 2018 , ... Finalists for the 2018 World ... product line was chosen for its advancements in the production chemicals category. The ... in upstream oil applications that are positively impacting the industry. The winners will ...
(Date:9/29/2018)... , ... September 29, 2018 , ... ... enabling mid-level and early-stage companies to access the power of influence analytics and ... solutions available to a broader market that didn’t necessarily have access to the ...
Breaking Biology Technology: