Navigation Links
Plant biologists discover unexpected proteins affecting small RNAs
Date:5/15/2008

LA JOLLA, CA - Now that high school biology students can recite that genes are made of DNA, which is transcribed into messenger RNA (mRNA), which is then translated into protein, along comes a new class of molecules, sending studentsand many scientistsscrambling for updated textbooks.

A study by Salk Institute for Biological Studies investigator Joseph Ecker, Ph.D., reported in the May 15, 2008 online issue of Developmental Cell, shows that the RNA world is more complex than imagined. Ecker and colleagues tinkered with factors that process mRNAs in the mustard weed Arabidopsis thaliana and observed affects on short, or small RNAs. Their findings could impact fields as diverse as plant pathology and cancer research.

Although they dont fit neatly into the DNA-to-mRNA-to-protein progression, small RNAs or microRNAs are the next big thing in both plant and animal molecular biology. Discovered a decade ago, numerous studies show that small RNAs put the brakes on the mRNA-to-protein step, by latching onto mRNA and blocking its translation into protein or causing its destruction, a phenomenon called RNA silencing.

Ecker, a professor in the Plant Biology Laboratory and director of the Salk Institute Genomic Analysis Laboratory, started by posing a simple genetic question. Researchers knew that eliminating either one of two proteinsone an mRNA-degrading enzyme called EIN5, and another a protein called ABH1 that binds to and protects mRNA from degradationcaused developmental defects in plants. Eckers group asked what the effects of mutating both simultaneously might be.

Aided by revolutionary deep-sequencing technology, which detects rare RNAs at high resolution, the investigators combed through the collection of all small RNAsknown as the smRNAomeand found that ein5/abh1 double mutant plants ramped up small RNA levels just enough to reveal something not seen before: the mutant plant cells were churning out small RNAs made from some of their own protein-coding mRNAs.

Investigators already knew that plants defend themselves against invading pathogens like viruses by generating short RNAs that recognize and silence foreign viral RNA. Observing that plants may silence their own RNAs in this manner was unanticipated. Our study shows that the way plants regulate RNAs produced in viruses is also probably the way they regulate their own genes, said Ecker. This has not been shown before in any organismplant or animal.

Ecker thinks this type of mRNA silencing is not an aberration of ein5/abh1 mutant plants. What we are seeing is in these mutants is probably a generic phenomenon that will likely hold true across all systems, said Ecker.

And why have these types of small RNAs not been observed before" Probably because researchers have not had the toolsnamely, the right mutants scrutinized by powerful new sequencing technologyto detect them until now.

Brian D. Gregory, Ph.D., a postdoctoral fellow in the Ecker lab and first author of the paper, feels that understanding small RNA activitywhether in a plant or animal cell settinghas implications for cancer research, a connection you might expect a plant biologist who is also recipient of the highly prestigious Damon Runyon fellowship for cancer research to make.

What we learn about RNA silencing pathways in plants could be applied to cancer chemotherapy, Gregory explained. There are genes expressed in tumor cells that protect them from being killed by chemotherapywe might be able to use small RNAs to antagonize the effect of these genes in cancer cells.

Ecker also sees the study as particularly timely in terms of ecological change. If you understand how plants respond normally to pathogens, you can rapidly make changes in that response, he said. If climate change occurs there is no doubt that insect pest populations will shift, and insects are what transmit viruses. Those insects will likely move into areas they have not seen before. Since small RNAs evolved to target invading pathogens, manipulating them may combat these effects.


'/>"/>

Contact: Gina Kirchweger
Kirchweger@salk.edu
858-453-410-01340
Salk Institute
Source:Eurekalert

Related biology news :

1. Circadian clock controls plant growth hormone
2. Layered approach may yield stronger, more successful bone implants
3. Clearance of hepatitis C viral infection after liver transplantation
4. Device helps patients survive, regain function til transplant
5. How the plant immune system can drive the formation of new species
6. The American Society of Plant Biologists announces 2007 awards
7. UCR plant cell biologist to study how plant stem cells maintain and change their identity
8. A study proposes a new universal rule to explain the equilibrium of plant populations
9. A study proposes a new universal rule to explain the equilibrium of plant populations
10. Study shows vitamin C is essential for plant growth
11. Clever plants chat over their own network
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/9/2016)... , UAE, May 9, 2016 ... when it comes to expanding freedom for high net ... Even in today,s globally connected world, there is ... conferencing system could ever duplicate sealing your deal with ... obtaining second passports by taking advantage of citizenship via ...
(Date:4/26/2016)... and LONDON , April ... part of EdgeVerve Systems, a product subsidiary of ... today announced a partnership to integrate the Onegini ...      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ) ... their customers enhanced security to access and transact ...
(Date:4/15/2016)... 15, 2016 Research and ... Biometrics Market 2016-2020,"  report to their offering.  , ... , ,The global gait biometrics market is expected ... the period 2016-2020. Gait analysis generates ... be used to compute factors that are not ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... , June 24, 2016  Regular discussions on a ... take place between the two entities said Poloz. ... Ottawa , he pointed to the country,s ... the federal government. ... said, "Both institutions have common economic goals, why not sit ...
(Date:6/23/2016)... ... June 23, 2016 , ... UAS ... the launch of their brand, UP4™ Probiotics, into Target stores nationwide. The company, ... proud to add Target to its list of well-respected retailers. This list includes ...
(Date:6/23/2016)... ... June 23, 2016 , ... Charm Sciences, Inc. ... test has received AOAC Research Institute approval 061601. , “This is another AOAC-RI ... stated Bob Salter, Vice President of Regulatory and Industrial Affairs. “The Peel Plate ...
(Date:6/23/2016)... ... , ... STACS DNA Inc., the sample tracking software company, today announced that ... joined STACS DNA as a Field Application Specialist. , “I am thrilled that ... of STACS DNA. “In further expanding our capacity as a scientific integrator, Hays brings ...
Breaking Biology Technology: