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Did peptides precede life on Earth? Should we be looking for their biosignatures on Mars?


If you think of DNA in correspondence terms, it writes instructions. RNA picks up the instructions and delivers them to a recipient in the cell. The instructions contain a recipe and what follows is the filling of it producing a protein molecule explicitly designed for the required task.

But before all of the above ever could have happened there had to be something with simpler chemistry. A research team at Rutgers University believes that what first emerged was probably a peptide containing the element nickel. They have named it Nickelback, not to be confused with a Canadian rock band of the same name. This Nickelback peptide consists of two bound nickel atoms which exhibit both stability and activity in terms of reacting with surrounding chemistry. Such a peptide is capable of redox reactions that transfer electrons from one chemical substance to another and is essential as the first stage on the way to life.

The Rutgers researchers believe that between 3.5 and 3.8 billion years ago, conditions in the water environment of early Earth led to the self-assembly of a pioneer peptide to become the precursor of proteins. With its emergence, metabolic processes began.

The research could be used to produce repellents for the insects.

Anyone who has ever been bitten by a mosquito has wondered why are these insects attracted to me? Now, Johns Hopkins Medicine researchers may have an answer, according to a press release published last month.

“Understanding the molecular biology of mosquito odor-sensing is key to developing new ways to avoid bites and the burdensome diseases they cause,” said Christopher Potter, Ph.D.


Panom/iStock.

They claim they have mapped specialized receptors on the insects’ nerve cells that are able to fine-tune their ability to detect particularly “welcoming” odors in human skin.

A series of three neuroimaging studies identified a pattern of neural activation involving specific brain regions that differentiates drug users from non-users with 82% accuracy. Researchers named the pattern the Neurobiological Craving Signature (NCS). Their findings have been published in Nature Neuroscience.

Craving is a strong desire to use drugs or eat. It has long been considered a key factor driving substance abuse and overeating. It is one of the criteria used for diagnosing substance use disorders. Craving is often induced by exposure to certain stimuli. In the case of overeating, these include the smell or sight of food. In the case of drugs, craving can be induced by one being in places or situations he/she associates with taking drugs or being offered drugs. This is called cue-induced craving.

Earlier studies of craving have successfully relied on self-reported craving, but recent research has focused on discovering its biological basis. Human neuroimaging studies have identified neural circuits related to the risk of substance abuse. Some brain circuits have been found to be involved in different substance use disorders and risky behaviors. These include specific parts of the ventromedial prefrontal cortex (vmPFC), ventral striatal/nucleus accumbens (VS/NAc) and insula regions of the brain. These regions also appear to play a role in weight gain and obesity.

Australian researchers have uncovered an enzyme capable of transforming air into energy. The study, which was recently published in the prestigious journal Nature, shows that the enzyme utilizes small amounts of hydrogen in the air to generate an electrical current. This breakthrough paves the way for the development of devices that can literally generate energy from thin air.

The discovery was made by a team of scientists led by Dr. Rhys Grinter, Ashleigh Kropp, a Ph.D. student, and Professor Chris Greening from the Monash University Biomedicine Discovery Institute in Melbourne, Australia. The team produced and studied a hydrogen-consuming enzyme sourced from a bacterium commonly found in soil.

Recent work by the team has shown that many bacteria use hydrogen from the atmosphere as an energy source in nutrient-poor environments. “We’ve known for some time that bacteria can use the trace hydrogen in the air as a source of energy to help them grow and survive, including in Antarctic soils, volcanic craters, and the deep ocean,” Professor Greening said. “But we didn’t know how they did this, until now.”

University of Virginia scientists have identified a promising approach to delay aging by detoxifying the body of glycerol and glyceraldehyde, harmful by-products of fat that naturally accumulate over time.

The new findings come from UVA researcher Eyleen Jorgelina O’Rourke, Ph.D., and her team, who are seeking to identify the mechanisms driving healthy aging and longevity. Their new work suggests a potential way to do so by reducing glycerol and glyceraldehyde’s health-draining effects.

“The discovery was unexpected. We went after a very well-supported hypothesis that the secret to longevity was the activation of a cell-rejuvenating process named autophagy and ended up finding an unrecognized mechanism of health and lifespan extension,” said O’Rourke, of UVA’s Department of Biology and the UVA School of Medicine’s Department of Cell Biology.

Recently is has become known that one should not take Metformin unless you have diabetes. But a combo test of Rapamycin and Metformin showed each removed each others side effects. So here we have another combo test showing the effect on stem cells in the gut.


In a new study published in Aging Cell, researchers have shown that two promising anti-aging agents, the antibiotic rapamycin and the anti-diabetic drug metformin, reverse aging in a population of intestinal stem cells [1].

Older people are more prone to gastrointestinal problems [2]. Moreover, aging is a major risk factor for various cancers, including colorectal cancer. Therefore, it is necessary to develop therapeutic approaches to rejuvenate the aging intestine.

The function and structure of the intestinal epithelium, a single cell layer that lines the small intestine and colon, is maintained by the residing stem cells. Intestinal stem cells continuously divide to generate several types of progenitor cells.

A new paper in Nature Communications illuminates how a previously poorly understood enzyme works in the cell. Many diseases are tied to chronic cellular stress, and UMBC’s Aaron T. Smith and colleagues discovered that this enzyme plays an important role in the cellular stress response. Better understanding how this enzyme functions and is controlled could lead to the discovery of new therapeutic targets for these diseases.

The enzyme is named ATE1, and it belongs to a family of enzymes called arginyl-tRNA transferases. These enzymes add arginine (an amino acid) to proteins, which often flags the proteins for destruction in the cell. Destroying proteins that are misfolded, often as a result of cellular stress, is important to prevent those proteins from wreaking havoc with cellular function. An accumulation of malfunctioning proteins can cause serious problems in the body, leading to diseases like Alzheimer’s or cancer, so being able to get rid of these proteins efficiently is key to long-term health.

The new paper demonstrates that ATE1 binds to clusters of iron and sulfur ions, and that the enzyme’s activity increases two-to three-fold when it is bound to one of these iron-sulfur clusters. What’s more, when the researchers blocked cells’ ability to produce the clusters, ATE1 activity decreased dramatically. They also found that ATE1 is highly sensitive to oxygen, which they believe relates to its role in moderating the cell’s stress response through a process known as .