Monthly Archives: January 2014

4 hours ago University of Chicago graduate student Xiao Wang and her colleagues based the results of their Nature paper on RNA modification on analysis of HeLa cells, a line of human cells widely used in laboratory research. Credit: Rob Kozloff/University of Chicago

Researchers had known for several decades that a certain chemical modification exists on messenger ribonucleic acid (mRNA), which is essential to the flow of genetic information. But only recently did experiments at the University of Chicago show that one major function of this modification governs the longevity and decay of RNA, a process critical to the development of healthy cells.

The chemical modification on mRNA in question is called N6-methyladenosine (m6A). A recent study by UChicago scientists reveals how the m6A modification on mRNA could affect the half life of mRNA that in turn regulates cellular protein quantities That discovery could provide fundamental insights into healthy functioning and disorders such as obesity, diabetes, and infertility.

The m6A modification "affects a huge number of messenger RNA in human cells, and yet we did not know its exact function," said Chuan He, professor in chemistry at UChicago and a recently selected investigator of the Howard Hughes Medical Institute. He, Xiao Wang and 11 co-authors from UChicago, University of California, San Diego, and Peking University reported their findings on m6A in the Jan. 2 issue of Nature.

RNA in human cells becomes constantly depleted as it produces proteins, an instability that is essential to biology. "Whenever a cells starts to differentiate, transform into a different type of cell, it needs to express a different set of proteins using a different set of messenger RNA," He said. "It can't be the original set."

The disposal of old RNA allows for the addition of new RNA and the production of different proteins. The Nature study documents that this process is regulated by the insertion or removal of a methyl, a chemical group commonly found in organic compounds.

"Biology is about protein expression regulation: which proteins, how many and at what point," He explained. "If you have the right pattern you get healthy cells. If you get the wrong pattern, you get disease."

It is well known that genetic factors can control protein expression, but the methylation and demethylation of RNA can be epigeneticoperating independent of the sequence of deoxyribonucleic acid (DNA). "This is a very important yet under-explored field," said Wang, the study's lead author and a graduate student in chemistry at UChicago. "It's also a field that is expanding very quickly."

Researchers had long known the presence of the m6A methylation on messenger RNA, but why this occurred remained unknown. He and his associates took a major step in 2011 when they discovered the reverse of the methylation process, demethylation. This discovery involved a so-called "eraser protein" that removed the methyl from RNA, a defect of which leads to obesity. "We basically said, 'Look, if you have certain defect of this function, you get obesity, so there's something going on fundamentally interesting. This methylation appears to play important roles in biological regulation."

He and his associates have now shown that the methylation affects the decay of messenger RNA. "People who are interested in messenger RNA decay or all kinds of cytoplasmic RNA biology now have a new pathway to consider," Wang said.

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Discovery spotlights key role of mystery RNA modification in cells

The End of Growth?

There is a school of thought that sees the first and second industrial revolutions as having been driven by specific innovations that are so unique and so fundamental that they are unlikely to be repeated. Where will we find any future innovation that is likely to have as much impact as the combustion engine or electricity or (pick your favorite)?

This is a widespread school of thought and is nowhere better illustrated than in the work of Dr. Robert Gordon, who is a professor of economics at Northwestern University and a Nobel laureate. I have previously written about his latest work, a papercalled Is US Economic Growth Over?

Before I audaciously suggest that he and other matriculants in his school of thought confuse theproductsof industrial revolutions with theircauses,and thus despair over the prospects for future growth, lets examine a little bit of what he actually says. (You can of course read the original paper, linked above.) To do that we can turn to an article by Benjamin Wallace-Wells that I cited inOutside the Boxlast June. He explains Robert Gordons views better than anyone I am aware of.

[T]he scope of his [Gordon's] bleakness has given him, over the past year, a newfound public profile, Wallace-Wells notes. Gordon offers us two key predictions, both discomfiting. The first pertains to the near future, when, he says, our economy will grow at less than half its average rate over the last century because of a whole raft of structural headwinds.

His second prediction is even more unsettling. He thinks the forces that drove the second industrial revolution (beginning in 1870 and originating largely in the US) were so powerful and so unique that they cannot be equaled in the future.

(A corollary view of Gordons, mentioned only indirectly in Wallace-Wellss article, is that computers and the internet and robotics and nanotech and biotech are no great shakes compared to the electric grid and internal combustion engine, as forces for economic change. Which is where he and I part company.)

Gordon thinks, in short, that we do not understood how lucky we have been, nor do we comprehend how desperately difficult our future is going to be. Quoting from Wallace-Wells:

What if everything weve come to think of as American is predicated on a freak coincidence of economic history? And what if that coincidence has run its course?

Picture this, arranged along a time line.

Follow this link:
John Mauldin Forecast 2014 - The Human Transformation Revolution

Quick guide to disaster recovery in the cloud

Boffins have devised a storage medium that could hold data for up to one billion years and claim recent accelerated ageing tests have shown "million-year" survivability.

The study's authors are Jeroen de Vries of the University of Twente MESA and Institute for Nanotechnology, and colleagues Dimitri Schellenberg, Leon Abelmann1, Andreas Manz and Miko Elwenspoek.

Their paper (PDF), in pre-print in ArXiv, is titled "Towards Gigayear Storage Using a Silicon-Nitride/Tungsten Based Medium".

Its abstract states: "If we want to preserve anything about the human race which can outlast the human race itself, we require a data storage medium designed to last for 1 million to 1 billion years."

Well, yes, er ... back to the technology.

The authors, involved with The Human Document Project, write: "To ensure that knowledge about human life is available for many future generations or even future lifeforms we require a form of data storage suitable for storage at extreme timescales."

The storage medium is "tungsten encapsulated by silicon nitride which, according to elevated temperature tests, will last for well over the suggested time."

Current 4TB hard drives can store data for about 10 years before the content starts decaying, the authors say. Tape will last a few decades and archival paper could last 500 years with the right environment.

The study's authors write: "A new type of storage medium is required where the longevity of the data is more important than the storage density," and this WORM-type medium should last for one million to one billion years with stored data being readable using electro-magnetic waves:

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'BILLION-YEAR DISK' to help FUTURE LIFEFORMS study us