Navigation Links
Built-in 'self-destruct timer' causes ultimate death of messenger RNA in cells
Date:12/22/2011

December 22, 2011(BRONX, NY) Researchers at Albert Einstein College of Medicine of Yeshiva University have discovered the first known mechanism by which cells control the survival of messenger RNA (mRNA) arguably biology's most important molecule. The findings pertain to mRNAs that help regulate cell division and could therefore have implications for reversing cancer's out-of-control cell division. The research is described in today's online edition of the journal Cell.

"The fate of the mRNA molecules we studied resembles a Greek tragedy," said the study's senior author, Robert Singer, Ph.D., co-director of the Gruss Lipper Biophotonics Center and professor and co-chair of anatomy and structural biology at Einstein. "Their lifespans are determined at the moment of their birth." The study was carried out in yeast cells using advanced microscope technology developed previously by Dr. Singer that has allowed scientists, for the first time, to observe single molecules in single cells in real time.

Directions for making proteins are encoded in the DNA sequences of genes, which reside on chromosomes in the nucleus of each cell. But for proteins to be made, a gene's DNA code must be copied, or transcribed, onto mRNA molecules, which migrate from the nucleus and into the cytoplasm where the cell's protein-making machinery is located. For as long as it exists, an mRNA molecule can act as a template for making copies of a protein. So scientists have long suspected that cells must have ways for degrading mRNAs when, for example, a protein starts accumulating to harmful levels. "The cell somehow decides to destroy its mRNA on cue, but nobody knew how this happens," said Dr. Singer.

In their search for such a mechanism, Dr. Singer and his colleagues focused on two genes, SWI5 and CLB2, which code for proteins that regulate the cell cyclethe complex series of steps during which a cell divides, first duplicating its genetic material and then distributing it evenly to two daughter cells. To properly choreograph the cell cycle, the levels of the proteins encoded by the SWI5 and CLB2 genes must be exquisitely controlledsuggesting that the mRNAs made from these genes would be prime candidates for purposeful degradation. Remarkably, the researchers found that these mRNAs are, in effect, born with molecular "self-destruct timers" that ultimately destroy them.

When genes are transcribed, a part of the gene called the promoter region has the job of switching on the gene so that DNA will be copied into mRNA. The Einstein scientists found that the promoter regions of the SWI5 and CLB2 genes do something else as well: they recruit a protein called Dbf2p, which jumps onto mRNA molecules as they're being synthesized.

These mRNAstranscribed from the SWI5 and CLB2 genes and bearing the Dbf2p proteinmake their journey from the nucleus into the cytoplasm. Here a protein called Dbf20p joins Dbf2p aboard the mRNA moleculesand the two proteins together call for the molecules' precipitous decay.

"Our findings indicate that genes making proteins whose levels must be carefully controlled contain promoter regions that sentence their mRNA molecules to death even as the mRNA is being born," said Dr. Singer. "The promoter regions do that by 'marking' the newly made mRNA with the protein Dbf2pthe common factor between mRNA synthesis and its ultimate decay. Dbf2p stays attached to the mRNA from its birth and then, responding to a signal indicating that no more protein should be made, orders mRNA's destruction."

While these observations pertain to yeast cells, Dr. Singer said he is confident that the process governing mRNA decay in humans "will prove to be very similar" and could be relevant for combating cancer. "Once you gain insight into the mechanisms controlling the cell cycle and cell division," he noted, "you can propose targeted therapies for regulating the uncontrolled cell division that characterizes cancer."


'/>"/>

Contact: Kim Newman
sciencenews@einstein.yu.edu
718-430-3101
Albert Einstein College of Medicine
Source:Eurekalert

Related biology news :

1. Fat serves as cells built-in pH sensor: UBC research
2. Built-in timer for improving accuracy of cost saving paper-strip medical tests
3. Scientists hope to end sleeping sickness by making parasite that causes it self-destruct
4. Self-destructing bacteria improve renewable biofuel production
5. These cells will self-destruct in 5...4...
6. High testosterone levels linked to self-destructive CEO behavior, says Management Science
7. NIMHs Dr. Mortimer Mishkin to be awarded National Medal of Science
8. What causes cell defenses to crumble?
9. Mercury pollution causes immune damage to harbor seals
10. Stomach ulcer bug causes bad breath
11. St. Jude identifies genomic causes of a certain type of leukemia relapse
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/15/2016)... and BADEN-BADEN, Germany , December 15, ... global financial services provider, today announced an agreement with NuData ... biometrics, to join forces. The partnership will enable clients to ... in compliance with local data protection regulation. ... In order to provide ...
(Date:12/15/2016)... Dec. 14, 2016 "Increase in mobile transactions ... The mobile biometrics market is expected to grow from ... by 2022, at a CAGR of 29.3% between 2016 ... as the growing demand for smart devices, government initiatives, ... "Software component is expected to grow at a ...
(Date:12/7/2016)... Israel , December 7, 2016 BioCatch ... the expansion of its patent portfolio, which grew to over 40 granted ... , , ... its recently filed patent entitled " System, Device, and Method ... technology that enables device makers to forego costly hardware components needed to ...
Breaking Biology News(10 mins):
(Date:1/23/2017)... 2017  Spherix Incorporated (Nasdaq: SPEX ) ... of technology and monetization of intellectual property, today provided ... Anthony Hayes , Chief Executive Officer of ... to communicate with shareholders about the status of existing ... on other patent assets that fit with our current ...
(Date:1/23/2017)... ... January 23, 2017 , ... Calvert Labs, Inc. announced ... and Senior Director, Safety Pharmacology. Dr. Thomas earned his M.Sc. and Ph.D. ... career as an academic and industry preclinical drug developer spans more than three ...
(Date:1/21/2017)... ... January 20, 2017 , ... ... resource to the healthcare industry ( http://www.gandlscientific.com ), has announced the opening of ... of clinical and scientific consultants and contractors. This is the latest step in ...
(Date:1/21/2017)... -- Bioptix, Inc. (Nasdaq: BIOP ... 14, 2017 the Board of Directors of the Company ... certain employees associated with the September 2016 acquisition of ... on January 16, 2017 and terminations are expected to ... severance benefits in certain circumstances of up to one ...
Breaking Biology Technology: