Rewrite the textbooks: Transcription is bidirectional

Jan 25, 2009

Genes that contain instructions for making proteins make up less than 2% of the human genome. Yet, for unknown reasons, most of our genome is transcribed into RNA. The same is true for many other organisms that are easier to study than humans.

Researchers in the groups of Lars Steinmetz at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, and Wolfgang Huber at the European Bioinformatics Institute (EMBL-EBI) in Hinxton, UK, have now unravelled how yeast generates its transcripts and have come a step closer to understanding their function.

The study, published online in Nature, redefines the concept of promoters (the start sites of transcription) contradicting the established notion that they support transcription in one direction only. The results are also representative of transcription in humans.

Investigating all transcripts produced in a yeast cell, the scientists found that most regions of the yeast genome produce several transcripts starting at the same promoter. These transcripts are interleaved and overlapping on the DNA. In contrast to what was previously thought, the vast majority of promoters seem to initiate transcription in both directions.

Not all of the produced transcripts are stable, many are degraded rapidly making it difficult to observe what they do. While some of the RNA molecules might be 'transcriptional noise' without function, other transcripts control the expression of genes and production of proteins. The act of transcription itself is also likely to play an important role in regulation of gene expression. Transcribing one stretch of DNA might either help or in other cases interfere with the transcription of a gene close by. Moreover, transcripts without a current purpose can serve as 'raw material for evolution' and acquire new functions over time.

The results shed light on the complex organisation of the yeast genome and the insights gained extend to transcription in humans. A better understanding of transcription mechanisms could find application in new technologies to tune gene regulation in the future.

Source: European Molecular Biology Laboratory

Explore further: Warning coloration paved the way for louder, more complex calls in certain species of poisonous frogs

add to favorites email to friend print save as pdf

Related Stories

Microsoft beefs up security protection in Windows 10

4 hours ago

What Microsoft users in business care deeply about—-a system architecture that supports efforts to get their work done efficiently; a work-centric menu to quickly access projects rather than weather readings ...

US official: Auto safety agency under review

17 hours ago

Transportation officials are reviewing the "safety culture" of the U.S. agency that oversees auto recalls, a senior Obama administration official said Friday. The National Highway Traffic Safety Administration has been criticized ...

Out-of-patience investors sell off Amazon

17 hours ago

Amazon has long acted like an ideal customer on its own website: a freewheeling big spender with no worries about balancing a checkbook. Investors confident in founder and CEO Jeff Bezos' invest-and-expand ...

Ebola.com domain sold for big payout

17 hours ago

The owners of the website Ebola.com have scored a big payday with the outbreak of the epidemic, selling the domain for more than $200,000 in cash and stock.

Recommended for you

Cat dentals fill you with dread?

Oct 24, 2014

A survey published this year found that over 50% of final year veterinary students in the UK do not feel confident either in discussing orodental problems with clients or in performing a detailed examination of the oral cavity ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

A_Paradox
not rated yet Jan 26, 2009
This is absolutely fascinating. It points, in one way, to genetic evolution being a kind of Heath-Robinson serendipity. In another way though it points to why multicellular life took thousands of millions of years to evolve, and to the amazing robustness of genomes which endure.