Scientists at The Scripps Research Institute have simultaneously mapped two of the most important types of protein-modification in cells, revealing their extensive cooperation during an essential cellular process.
Phosphorylation, the attachment of a phosphate group to a protein, and proteolysis, the cleavage of a protein, had almost always been studied independently. The new research combines techniques for mapping these events across all proteins in a cell population to show how they work together to execute the cellular "auto-destruct program" known as apoptosis.
The specific findings on apoptosis may lead to the development of new cancer diagnostics and drugs, since cancer treatments often aim to induce apoptosis in malignant cells. Even more importantly, the study marks the development of a basic new tool of "proteomics" -- the large-scale study of proteins -- that should provide useful insights into many cellular processes.
"Detecting the cross-talk between protein regulation pathways has long been a challenge, and so with this new technique we can start to do analyses that were difficult or impossible before," said Benjamin F. Cravatt, professor and chair of the Department of Chemical Physiology at Scripps Research, and member of Scripps Research's Skaggs Institute for Chemical Biology. Cravatt was the senior investigator for the study, published in the July 20, 2012 edition of the journal Cell.
Science & Technology
© Dian Fossey Gorilla Fund
Wild gorillas Rwema and Dukore destroy a primitive snare in Rwanda earlier this week.
Wild gorillas Rwema and Dukore destroy a primitive snare in Rwanda earlier this week.
"This is absolutely the first time that we've seen juveniles doing that ... I don't know of any other reports in the world of juveniles destroying snares," said Veronica Vecellio, gorilla program coordinator at the Dian Fossey Gorilla Fund's Karisoke Research Center, located in the reserve where the event took place.
"We are the largest database and observer of wild gorillas ... so I would be very surprised if somebody else has seen that," Vecellio added.
Bush-meat hunters set thousands of rope-and-branch snares in Rwanda's Volcanoes National Park, where the mountain gorillas live. The traps are intended for antelope and other species but sometimes capture the apes.
Adults are generally strong enough to free themselves. Youngsters aren't always so lucky.
Just last week an ensnared infant named Ngwino, found too late by workers from Karisoke, died of snare-related wounds. Her shoulder had been dislocated during escape attempts, and gangrene had set in after the ropes cut deep into her leg.
The hunters, Vecellio said, seem to have no interest in the gorillas. Even small apes, which would be relatively easy to carry away for sale, are left to die.
© Lingsen Meng
Also, the so-called intraplate quake is the largest ever measured for a fault zone for which the two sides of the fault slide horizontally past each other, a la the San Andreas fault, rather than having one side of the fault shoved beneath its neighbor. The epicenter of the quake (denoted with a star, above) was located about 400 kilometers southwest of the magnitude-9.1, tsunami-spawning temblor that occurred off the northwestern coast of Sumatra on 26 December 2004 (areas affected by largest slippage of that quake are depicted in red, orange, and yellow at upper right; northwestern tip of Sumatra depicted in gray silhouette).
Over the course of about a minute and a half, this spring's temblor ruptured 500 kilometers of three separate but related faults, all of which were highly stressed. A lot of that stress was shifted to the area by the December 2004 quake, the researchers suggest. The faults unzipped at a relatively slow but steady 2.5 kilometers per second, the researchers say, with much of the slippage along the faults taking place more than 25 kilometers below the seafloor - a depth that helped contribute to the quake's great magnitude.
© 2045 Initiative
Avatar 2045 Goals.
Avatar 2045 Goals.
"Many of you who have accumulated great wealth by making success of your businesses are supporting science, the arts and charities. I urge you to take note of the vital importance of funding scientific development in the field of cybernetic immortality and the artificial body," Itskov wrote in the letter. "Such research has the potential to free you, as well as the majority of all people on our planet, from disease, old age and even death."
The 2045 Initiative claims to have hired 30 scientists to help it pursue its immortality goal. It is opening a San Francisco office this summer and launching a major social media effort to get scientists talking about cybernetic technologies. It's hosting another Global Future Congress next year in New York City (the last one was in Moscow earlier this year). In other words, as crazy as this sounds Itskov is dead serious and the wheels are turning on this project.
© Carolina K. Smith, M.D., Shutterstock
Human sperm cells under 100x magnification.
Human sperm cells under 100x magnification.
The findings, reported today (July 19) in the journal Cell, may help researchers understand the genetic mixing that ensures that babies end up with an even blend of DNA.
A new understanding of the sperm genome may have "far-ranging implications for the study of cancer, infertility and many other disorders," study researcher Stephen Quake, a bioengineer at Stanford University, said in a statement.
Quake and his colleagues sequenced the genomes of 91 sperm cells from a 40-year-old man with a healthy semen sample and normal children. They found a surprising level of variability between the cells. For example, two of the sperm cells were missing entire chromosomes.
Gametes -- egg cells and sperm cells -- hold half of the amount DNA found other cells of an organism. A human cell has 23 pairs of matched chromosomes, or bundles of DNA; sperm and egg cells have 23 single chromosomes.
© Unknown
Artists depiction of carbon transistors.
Artists depiction of carbon transistors.
If claims made by scientists at Tel Aviv University (TAU) are to be believed, the transistors consisting of C60 molecules (the name is derived from a 60 carbon atom structure) can be built in a smaller sizes and could operate much more efficiently.
Elad Mentovich from TAU found that other than silicon transistors, his C60 transistors can both store and transfer energy and do not need the capacitor that is required for a silicon transistor. The result would be more room for transistors and reduced energy consumption. According to Mentovich, the carbon transistors could be built as small as 1 nm and manufactured on today's manufacturing equipment.
"When this new technology is integrated into future devices, you will have much more memory on your smartphones and tablets, approaching the level of a laptop," Mentovich said. "With that kind of memory, you'll be able to run applications simultaneously, and because it is low voltage, power consumption will fall and battery life will be longer." There was no information on the potential performance of the C60 transistors.
The next phase of the research is to find a production fab that will actually produce the transistors.
These are the stunning images of the Northern Lights caught making a very rare appearance above the Essex skyline. The phenomenon, where charged particles from the sun cause the sky to blaze green and red is more normally seen further north in Norway or the North of Scotland. Residents near the town of Maldon were treated to the night time spectacular which is very rarely seen anywhere in the South of England.
© Peter Scott
Purple haze: Residents near the town of Maldon were treated to the night time spectacular which is very rarely seen anywhere in the South of England (as in, NEVER seen)
Purple haze: Residents near the town of Maldon were treated to the night time spectacular which is very rarely seen anywhere in the South of England (as in, NEVER seen)
Nasa scientists are baffled as to what - or maybe even who? - created this unusual hole on the surface of Mars.
The hole was discovered by chance on images of the dusty slopes of the Red Planet's Pavonis Mons volcano. It appears to be an opening to an underground cavern, partly illuminated to the right of the opening.
The hole was discovered by chance on images of the dusty slopes of the Red Planet's Pavonis Mons volcano. It appears to be an opening to an underground cavern, partly illuminated to the right of the opening.
© NASA
A hole in Mars: The opening was discovered by chance on images of the dusty slopes of the Red Planet's Pavonis Mons volcano
A hole in Mars: The opening was discovered by chance on images of the dusty slopes of the Red Planet's Pavonis Mons volcano
© J. Major
Check it out...
The image above was created from Cassini raw images acquired in red, green, and blue color channels and assembled to create a somewhat "true-color" image of Saturn. The image shows the storm as it looked on February 25, 2011, a couple of months after it was first noticed by amateur astronomers on the ground. (The circle at upper left illustrates the comparative size of Earth.)
© Image courtesy of University of California - Santa Barbara
A graphic representing the action of the Dam enzyme on E. coli DNA. The blue circles represent methylation "tags" which are added to the GATC sites on the bacteria's DNA. The clustering of the GATC sites, as seen in the top panel, facilitates Dam's "intrasite hopping" which causes the expression of the pili.
A graphic representing the action of the Dam enzyme on E. coli DNA. The blue circles represent methylation "tags" which are added to the GATC sites on the bacteria's DNA. The clustering of the GATC sites, as seen in the top panel, facilitates Dam's "intrasite hopping" which causes the expression of the pili.
The E. coli bacteria's adaptive mechanism allows it to change its phenotype -- its observable characteristics -- according to its environment. For example, if it senses a need to find food, to stick to the tissues of its host organism, or to reproduce, the bacteria will form pili, or hairlike structures, on its surface, to allow it to move, stick, or pass genetic material.
"We're trying to figure out what is it in the cell that's driving those changes," said Adam Pollak, first author of the paper.
The formation of these pili is driven by an epigenetic mechanism -- a "tagging" done by the enzyme DNA adenine methyltransferase (Dam), which acts on a specific sequence of DNA, called GATC sites (Guanine-Adenine-Thymine-Cytosine). The tagging signals the formation of these -- appendages a mechanism similar to that in humans, where tagging directs the formation of tissues for different organs from the same DNA. This tagging is part of a broader field, called epigenetics, where modifications made to the genome are heritable and regulate the expression of genes.
