Three stories today. An amino acid known for building muscle turns out to guard the cell's power plants as well, and a way to hide an invisible signature inside proteins designed by machines has been released. And a warming atmosphere, it is calculated, is lengthening the day by a little.
Life
Leucine, an amino acid, keeps proteins on the outer skin of mitochondria from being cleared away, so the cell makes energy better.
Leucine is one of the amino acids used to weave proteins. There is plenty of it in milk, meat and beans, and because it matters for building muscle, people who train often take it.
Researchers at the University of Cologne watched leucine doing a different job. Inside a cell there is a clean-up system that finds broken proteins and takes them away. It also takes away a few useful ones. Among those lost are proteins on the outer skin of the mitochondria that help make energy. When leucine is plentiful the clean-up system works more slowly, those proteins last longer, and the cell makes energy better. The team saw this in human cells and in a tiny worm. But slowing the clean-up has a price: broken proteins piling up do harm as well.
Through the eyes of the AtlasLynn Margulis argued that mitochondria were once bacteria that moved into the cell. That guest-turned-power-plant still plays tug of war with the cell's rules about cleaning house. Today's story says one end of that rope is in the food we eat.
A word of cautionThis is basic research. It is not a reason to take more leucine, and the team said plainly that making more energy is not always a good thing.
Source · ScienceDaily (University of Cologne)
Technology
Google DeepMind has shown a way to put a readable mark inside the amino-acid order of an AI-designed protein without touching what the protein does.
A protein is a long chain of amino acids, and their order decides its shape and its work. These days machines design such orders to do a job we ask for. That helps in making medicines and new materials, but it also brings a problem: you cannot tell who designed a given sequence.
The method leans on the fact that many different orders do the same job. If you pick the one that fits a rule agreed in advance, the protein looks ordinary, yet anyone who knows the rule can read the mark. Tested on proteins made to stick to three targets, the marked and unmarked versions held on and folded almost identically. The point is that when designs are added to open databases, it stays possible to tell which ones a machine wrote.
Through the eyes of the AtlasThe library piece on biologics is about getting living things to build what we cannot build ourselves. Now a machine draws the plan. The machine described in "How Does an AI Learn?" has begun writing parts of living things rather than sentences, and that is why a signature is wanted.
A word of cautionThis comes from a company, and the results are from the laboratory. Whether the mark survives someone deliberately trying to rub it out is another matter.
Source · Google DeepMind
Earth
As warming rearranges the great wind patterns, the air carries more spin — and the solid Earth turns that much more slowly, a new calculation finds.
How fast the Earth turns is not the ground's business alone. The air above turns with it, and ground and air trade spin through friction. When the air carries more spin, the ground turns a little slower, in the way a skater slows down by spreading their arms.
Researchers at the IBS Center for Climate Physics and Pusan National University in Korea ran three climate models many times over to see how the great wind patterns change in a warmer world. The big circulation that rises at the equator and sinks in the middle latitudes spreads towards both poles, the fast winds high over the middle latitudes strengthen, and the trade winds near the equator weaken. Together these make the air carry more spin. By 2100 the lengthening of the day from this could amount to a tenth or a fifth of the lengthening caused by tidal friction from the Moon.
Through the eyes of the AtlasOn 30 September this column carried the news that the day's length wobbles because the Earth's inner core and mantle pull on each other. Today's story is the share added from outside. As "Measuring with the Same Ruler" explains, a second is now set by the trembling of atoms, which is why the Earth slowing by a hair shows up as a number at all.
A word of cautionThis is a calculation run in climate models, and it assumes a high-emissions world. The largest share of the wobble in the day's length still comes from the core and mantle deep inside.
Source · Phys.org (IBS Center for Climate Physics · Pusan National University)