Author: Serkadis

For the first time, researchers have found a particular kind of molecular switch in the food poisoning bacteria Salmonella Typhimurium under infection-like conditions. This switch, using a process called S-thiolation, appears to be used by the bacteria to respond to changes in the environment during infection and might protect it from harm, researchers report this week online in the Proceedings of the National Academy of Sciences Early Edition.

S-thiolation protects proteins from irreversible chemical changes when a cell is stressed. The newly discovered switch might regulate when or how proteins work while offering protection, providing researchers insight into Salmonella infection.

“We continue to recognize just how clever this bug is in adapting to its environment,” said systems biologist Josh Adkins of the Department of Energy’s Pacific Northwest National Laboratory. “During infection it lives in hostile environments, and so it can use multiple approaches to adjust its functions.”

Whole Ensemble

Salmonella Typhimurium causes food poisoning in people and can be fatal in the elderly or very young. Recent technological advances in the field known as proteomics are allowing researchers to explore how proteins, the workhorses of the cell, allow the bacteria to infect and cause illness. Most technologies that examine a cell’s ensemble of proteins do so by chopping the proteins up. Adkins, lead author Charles Ansong and other colleagues wanted to look at whole proteins, which provides more information such as how proteins are regulated.

Cells regulate how proteins work in several ways. One of the most common adds molecular pieces that serve as gas pedals on proteins, turning them up or down in a grand orchestrated way. Proteomics methods that chop up proteins allow a researcher to determine that a particular protein was present, but not if it was actually functioning. Those methods also destroy evidence about how hard the gas pedal was pressed.

To identify which proteins were likely turned on or off during Salmonella infection, the team grew the bacteria either with rich food that satisfied all their nutritional needs or with nutrient-poor food that mimicked the kind of stressful environment the microbes find themselves in while infecting someone.

Then the researchers took samples of the bacteria and identified the proteins inside. They used a method called top-down proteomics, a technological advancement that allows researchers to look at wide swaths of whole proteins instead of just a few at a time. The team identified 563 unique proteins. This number is comparable to fungus and human studies but almost three times as many as in other bacterial studies using top-down proteomics.

They also determined if the proteins had molecular modifications on them. These can cap an end of a protein or dot the protein’s length. Because different modifications can be mixed and matched on one protein, they ended up with a total of 1,665 different forms of the 563 unique proteins.

“This study shows how well top-down proteomics works, especially to get at regulatory information,” said co-author Ljiljana Pasa-Tolic, who led top-down proteomics development with mass spectroscopist Si Wu at EMSL, DOE’s Environmental Molecular Sciences Laboratory on the PNNL campus.

Gluts Versus Cysts

Of particular interest to the team were S-thiolation modifications. These modifications cover and protect a protein’s sulfur atoms, which tend to snag each other like velcro and cause misshapen proteins. The modifications come in two flavors: a bulky glutathione and a compact cysteine. While glutathione modifications are pretty well studied, only four studies reveal cysteine modifications, and only two of those are in bacteria.

A total of 25 proteins sported glutathiones and another 18 wore cysteines. But nine of these stood out: The glutathiones and the cysteines attached to the same exact spot on the nine proteins. Not at the same time — the team found that Salmonella used glutathiones at these sites when they were fat and happy, growing with rich food. When grown under stressful conditions with nutritionally poor food, the Salmonella swapped their glutathiones for cysteines.

In addition, switching S-thiolation modifications appeared to be a talent unique to Salmonella. The team checked other bacteria such as Escherichia coli, a common gut bacteria, and Yersinia pestis, which causes plague, to see if other species used this S-thiolation switch on their proteins. They didn’t, suggesting that Salmonella had come up with this tactic during its own evolution.

The researchers speculate that Salmonella might use the smaller cysteine under stressed conditions as an energy saving device. Additional research will reveal what control functions the modifications are actually performing on the proteins, as well as explore how global this method of control is within the microbe.

This work was supported by the National Institute of Allergy and Infectious Disease through interagency agreement Y1-AI-8494-01 and the National Institute for General Medical Sciences.

Reference: Charles Ansong, Si Wu, Da Meng, Xiaowen Liu, Heather Brewer, Brooke L. Deatherage Kaiser, Ernesto S. Nakayasu, John R. Cort, Pavel A. Pevzner, Richard D. Smith, Fred Heffron, Joshua N. Adkins and Ljiljana Paša-Tolic. Top-down proteomics reveals a unique protein S-thiolation switch in Salmonella Typhimurium in response to infection-like conditions, Proc Natl Acad Sci U S A, Early Edition online the week of May 27, 2013, DOI 10.1073/pnas.1221210110.

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Here’s a roundup of some of this week’s headlines from the network sector:

Ciena and BT light 800G Super-Channel.  Ciena (CIEN) and BT announced a series of pioneering trials over BT’s UK optical core network infrastructure. The successful trials in March 2013 included the transmission of 100, 200, and 400G, as well as an “800G super-channel,” the last of which equates to the simultaneous transmission of seven High Definition DVDs in a single second. The trials were performed on a high Polarization Mode Dispersion (PMD) fibre link between BT’s Adastral Park Research and Development Centre in Ipswich and the iconic BT Tower in Central London. “These high capacity transmission demonstrations illustrate the value of Ciena and BT’s long-standing strategic relationship,” said François Locoh-Donou, senior vice president, global products at Ciena. “BT’s future-proof network will enable it to stay ahead of the competition and continue to offer customers cutting-edge services, while minimising its overall cost-base and carbon footprint. With this collaboration agreement, we can further deepen our relationship and work together to build service-enabling and highly-programmable networks, leveraging Ciena’s entire product portfolio to jointly develop ground-breaking services and applications for BT’s customers.” Ciena also announced that the Russian carrier RASCOM is deploying its 6500 Packet-Optical Platform  to support the 100G upgrade and network expansion of a route connecting Russia to Western Europe.

Cisco selected by Chinese cable operator Zhejiang Wasu.  Cisco (CSCO) announced that Zhejiang Wasu Cable TV Network Co., Ltd. (Wasu), one of the leading cable operators in China, has successfully deployed a new 100G Internet Protocol and Dense Wave Division Multiplexing (IP+DWDM) backbone network to better support cloud-based video and data services. Wasu’s new cloud computing platforms will rely on the Cisco ASR 9000 Aggregation Services Router and coherent DWDM line cards on the Cisco ONS 15454 Multiservice Transport Platform (MSTP). ”The broadcasting industry is undergoing tremendous changes and transformations,” said Cisco vice president, Hanh Tu. “Taking advantage of our leading network and video technologies, Cisco strives to provide the most comprehensive network and video solutions for China’s operators, to help them maximize their business value. We are honored to help Wasu deploy its new network, so that it can provide new video experiences and services for its subscribers.”

Level 3 to broadcast Fox UEFA Soccer.  Level 3 Communications (LVLT)  announced it is providing video broadcast services to enable FOX Network to deliver the live feed of the Union of European Football Associations’ (UEFA) annual championship soccer final to viewers across the U.S.  Level 3′s global fiber network is directly connected to Wembley Stadium, which allows Level 3 to deploy its Vyvx Solutions to provide an end-to-end video broadcast solution to FOX. Level 3 will take the feed from the game in London and deliver it to FOX Network, FOX Soccer Channel and FOX Deportes in Los Angeles for distribution to U.S. viewers. ”The quality of a broadcast can help make or break a viewing experience for sports fans, so it’s critical that FOX ensures its ability to deliver its content in a seamless, efficient and secure manner,” said Mark Taylor, vice president of Media and IP Services at Level 3. “Level 3 is proud to provide FOX Network, FOX Soccer Channel and FOX Deportes, with a comprehensive suite of broadcast services that ensures viewers will be able to enjoy every moment of the UEFA Champions League final.” Level 3 also announced it is providing content delivery network (CDN), high-speed IP (HSIP) and colocation services for Metaboli, a leading European distributor of Internet-based video games.

(NaturalNews)Ever since I was a kid growing up in Newark I centered on sports. It started with playing all kinds of running games, then punch ball, then stick ball, then varsity sports in high school (football, swimming and track) and college (freestyle, butterfly and individual…

Take off your silken cloak and get your dragon eggs ready because Cyvasse, the game that characters play in George R. R. Martin’s Game Of Thrones series is now 3D-printable. Created by Arian Croft of IllGottenGames and his friend Nate Stephens, the game uses most of Martin’s rules mentioned in the books as well as interpolations taken from period-specific game rules.

He writes:

The pieces are nicely detailed but should print well on even simpler 3D printers. I’ve printed one of Arian’s previous games, Pocket-Tactics and he’s an excellent model-maker with a good eye for detail and an understanding of the limitations of the medium. Best of all, this game is free to print and play, a potential disruption that should should be giving Parker Brother’s nightmares.

You can download the game here and print it out yourself in black or white ABS. Just don’t tell those nasty Warlocks in Qarth. They’ll probably steal all your pieces.

via reddit