Biologists unlock code regulating most human genes

Biologists unlock code regulating most human genes
Credit: University of California - San Diego

Molecular biologists at UC San Diego have unlocked the code that initiates transcription and regulates the activity of more than half of all human genes, an achievement that should provide scientists with a better understanding of how human genes are turned on and off.

The discovery of this critical DNA sequence code—what molecular biologists term the "human Initiator"—is detailed in a paper in the February 10 print issue of the journal Genes & Development.

"There are many sequence signals that control gene activity in human cells and the Initiator is the most commonly occurring sequence at the start sites of genes," says James T. Kadonaga, a molecular biology professor at UC San Diego who headed the team of researchers. "The solution of the human Initiator code will enable us to explore new frontiers in gene regulation. In the future, it will be possible to use the code to identify other regulatory signals and, in this way, gain a more complete understanding of how human genes are turned on and off."

Each tiny human cell contains about six feet of DNA, a double-helical molecular chain containing several billion chemical nucleotides—adenosine (A), cytosine (C), guanine (G) and tyrosine (T)—arranged in a specific sequence, or code, that when transcribed guide the cell into producing specific proteins.

"In these six feet of DNA, there are tens of thousands of genes, which are segments of DNA that direct specific functions, such as the production of a hormone or an enzyme," explains Kadonaga. "It is essential for the cell to control the activity of each of its tens of thousands of genes, because the improper control of can lead to adverse outcomes such as cell death or the formation of a cancer cell."

That's where the human Initiator comes in.

First observed by Pierre Chambon and his colleagues in Strasbourg, France in 1980, the human Initiator and its role in gene activation were articulated in 1989 by two MIT biologists, Stephen Smale and David Baltimore at MIT, who revealed in the 1990s, the approximate sequence code of the Initiator.

Since then, however, other scientists had proposed a number of different sequences for the human Initiator, but none of them were found to be consistently associated with the start sites of human genes. As a result, the true Initiator sequence code remained a mystery until now.

Kadonaga and his team employed emerging genomic techniques and devised novel computational strategies to unlock the DNA sequence code for the human Initiator. They also discovered that this sequence is located precisely at the start site of more than half of all , underlining the importance of the human Initiator in the human genome.


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Journal information: Genes & Development

Citation: Biologists unlock code regulating most human genes (2017, January 24) retrieved 22 August 2019 from https://phys.org/news/2017-01-biologists-code-human-genes.html
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Jan 24, 2017
Well done to the researchers.
Now if ever there was a clear indication that biological life is the result of a super-intelligent mind, this is it:
unlocked the code


A code and its corresponding decoding can only exist because an intelligent mind designed it that way. For any code to have meaning there must be some external understanding attached to it which is independent of the media in which it is located.
The existence of the over abundance of codes which require corresponding decoders means simply that it's impossible for life to have arisen from naturalistic causes all by itself. Such an idea is simply irrational in view of what we know about the operations of the cell today.

Jan 25, 2017
A code and its corresponding decoding can only exist because an intelligent mind designed it that way.
Exactly! Much like ice never forming before we discovered the freezing point of water.

Jan 25, 2017
In this context, "code" does not mean what you think it does, Fred. It's standard journalistic colloquialism for
"a sequence that has evolved over billions of years and trillions of iterations to accurately replicate".

Jan 25, 2017
In this context, "code" does not mean what you think it does, Fred. It's standard journalistic colloquialism for "a sequence that has evolved over billions of years and trillions of iterations to accurately replicate".


So, the term ironically refers to genetic sequences as code, as, in actuality, no information is stored or retrieved. It's all just random combinations that magically result in multiple inter-functional systems. If a genetic sequence contains information, that information must have derived from some source, a source capable of storing it accurately for later use.

Jan 26, 2017
So, the term ironically refers to genetic sequences as code, as, in actuality, no information is stored or retrieved.
It's all just random combinations that magically result in multiple inter-functional systems. If a genetic sequence contains information, that information must have derived from some source, a source capable of storing it accurately for later use.

Info IS stored. Starting at the atomic level via electron coupling structure of an element to itself or another. No magic involved. By the time you get to the "multiple inter-functional systems" you refer to, there are millions, if not billions, of "crystallization" (electron coupling) events that have fixed into a structure.
That's a LOT of info...

Jan 26, 2017
Of course DNA stores information; the information is the sequences of amino acids that make up the proteins that our bodies use to live. Claiming that's "not information" is silly.

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