Plant research reveals new role for gene silencing DICER protein

Mar 29, 2012

A DICER protein, known to produce tiny RNAs in cells, also helps complete an important step in gene expression, according to research on Arabidopsis thaliana.

The expression of a gene, when an organism's DNA is transcribed into a useable product, requires activation via a promoter or an external trigger. Plant research to be published in Science helps to show that later stages of transcription are just as important. This is likely to apply to other organisms, including humans.

Termination is the final stage of transcription. Successful termination is dependent on DNA being transcribed into RNA with the correct sections, including a certain length tail.

Scientists at the John Innes Centre on Norwich Research Park have found that where effective termination through the normal mechanisms has not occurred, DICER-LIKE 4 (DCL4) steps in to tidy up. Without termination, transcription continues down the chromosome unchecked.

In this way, DCL4 plays a crucial and previously unknown role in transcription termination. It helps formation of the . DCL4 is more commonly known to play a part in the opposite effect, gene silencing.

"DCL4 is a back-up to termination processes, helping a gene to be successfully expressed," said lead author Professor Caroline Dean from JIC, which is strategically funded by the BBSRC.

The findings may help explain why gene silencing happens so often with . It was not known that so much attention should be given to the tail end of a gene.

"Our research shows that for successful expression the end of a gene is just as important as its beginning," said Dean.

When termination fails a lot of aberrant RNA is made – this is degraded as part of a cell's quality control mechanism. This can have consequences for other sequences in the genome that match the aberrant RNA.

"If a gene ends badly, aberrant will trigger silencing pathways," said Dean.

DCL4's ability to step in to rescue poor termination makes it important for both successful , a previously unknown role for it, and gene silencing.

Explore further: Heaven scent: Finding may help restore fragrance to roses

More information: "Cotranscriptional Role for Arabidopsis DICER-LIKE 4 in Transcription Termination" Science, doi 10.1126/science.1214402

Related Stories

Novel mechanism for control of gene expression revealed

Mar 04, 2011

Dr. David Levin, Professor of Molecular & Cell Biology at Boston University Henry M. Goldman School of Dental Medicine and Professor of Microbiology at Boston University School of Medicine discovered recently a novel, evolutionarily ...

Scientists observe single gene activity in living cells

Apr 21, 2011

Researchers at Albert Einstein College of Medicine of Yeshiva University have for the first time observed the activity of a single gene in living cells. In an unprecedented study, published in the April 22 online edition ...

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 ...

Silence of the genes

Jul 22, 2011

A molecular mechanism by which gene silencing is regulated at the genome-wide level in plants has been uncovered by a research team led by Motoaki Seki of the RIKEN Plant Science Center, Yokohama, Japan. ...

Recommended for you

Study on pesticides in lab rat feed causes a stir

Jul 02, 2015

French scientists published evidence Thursday of pesticide contamination of lab rat feed which they said discredited historic toxicity studies, though commentators questioned the analysis.

International consortium to study plant fertility evolution

Jul 02, 2015

Mark Johnson, associate professor of biology, has joined a consortium of seven other researchers in four European countries to develop the fullest understanding yet of how fertilization evolved in flowering plants. The research, ...

Making the biofuels process safer for microbes

Jul 02, 2015

A team of investigators at the University of Wisconsin-Madison and Michigan State University have created a process for making the work environment less toxic—literally—for the organisms that do the heavy ...

Why GM food is so hard to sell to a wary public

Jul 02, 2015

Whether commanding the attention of rock star Neil Young or apparently being supported by the former head of Greenpeace, genetically modified food is almost always in the news – and often in a negative ...

The hidden treasure in RNA-seq

Jul 01, 2015

Michael Stadler and his team at the Friedrich Miescher institute for Biomedical Research (FMI) have developed a novel computational approach to analyze RNA-seq data. By comparing intronic and exonic RNA reads, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.