Navigation Links
Lost in translation
Date:1/7/2009

The enzyme machine that translates a cell's DNA code into the proteins of life is nothing if not an editorial perfectionist.

Johns Hopkins researchers, reporting this week in Nature, have discovered a new "proofreading step" during which the suite of translational tools called the ribosome recognizes errors, just after making them, and definitively responds by hitting its version of a "delete" button.

It turns out, the Johns Hopkins researchers say, that the ribosome exerts far tighter quality control than anyone ever suspected over its precious protein products which, as workhorses of the cell, carry out the very business of life.

"What we now know is that in the event of miscoding, the ribosome cuts the bond and aborts the protein-in-progress, end of story," says Rachel Green, a Howard Hughes Medical Institute investigator and professor of molecular biology and genetics in the Johns Hopkins University School of Medicine. "There's no second chance." Previously, Green says, molecular biologists thought the ribosome tightly managed its actions only prior to the actual incorporation of the next building block by being super-selective about which chemical ingredients it allows to enter the process.

Because a protein's chemical "shape" dictates its function, mistakes in translating assembly codes can be toxic to cells, resulting in the misfolding of proteins often associated with neurodegenerative conditions. Working with bacterial ribosomes, Green and her team watched them react to lab-induced chemical errors and were surprised to see that the protein-manufacturing process didn't proceed as usual, getting past the error and continuing its "walk" along the DNA's protein-encoding genetic messages.

"We thought that once the mistake was made, it would have just gone on to make the next bond and the next," Green says. "But instead, we noticed that one mistake on the ribosomal assembly line begets another, and it's this compounding of errors that leads to the partially finished protein being tossed into the cellular trash," she adds.

To their further surprise, the ribosome lets go of error-laden proteins 10,000 times faster than it would normally release error-free proteins, a rate of destruction that Green says is "shocking" and reveals just how much of a stickler the ribosome is about high-fidelity protein synthesis.

"These are not subtle numbers," she says, noting that there's a clear biological cost for this ribosomal editing and jettisoning of errors, but a necessary expense.

"The cell is a wasteful system in that it makes something and then says, forget it, throw it out," Green concedes. "But it's evidently worth the waste to increase fidelity. There are places in life where fidelity matters."


'/>"/>

Contact: Maryalice Yakutchik
myakutc1@jhmi.edu
443-287-2251
Johns Hopkins Medical Institutions
Source:Eurekalert

Related biology news :

1. New York Stem Cell Foundation announces third annual Translational Stem Cell Research Conference
2. Study reveals surprising details of the evolution of protein translation
3. NIH expands national consortium dedicated to transforming clinical and translational research
4. Improving care and knowledge in translational research to fight breast cancer
5. Translational research patented first experimental treatment against idiopathic pulmonary fibrosis
6. Shilatifard Lab sheds light on molecular machinery required for translation of histone crosstalk
7. AACR, BCRF award inaugural grants in translational breast cancer research
8. NIH awards nearly $23M to University of Chicago for translational research
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/16/2017)... 16, 2017  Genos, a community for personal ... has received Laboratory Accreditation from the College of ... to laboratories that meet stringent requirements around quality, ... processes. "Genos is committed to maintaining ... We,re honored to be receiving CAP accreditation," said ...
(Date:2/13/2017)... 2017  RSA Conference -- RSA, a Dell Technologies ... to enhance fraud detection and investigation across digital ... Fraud & Risk Intelligence Suite. The new platform ... insights from internal and external sources as well ... customers from targeted cybercrime attacks. "Fraudsters ...
(Date:2/10/2017)... Research and Markets has announced the addition of ... Commercial Aspects" to their offering. ... Biomarkers play an important ... selection of treatment as well for monitoring the results. There ... modern medicine. Biochip/microarray technologies and next generation sequencing are also ...
Breaking Biology News(10 mins):
(Date:2/24/2017)... 24, 2017  OncoSec Medical Incorporated ("OncoSec") (NASDAQ: ONCS), ... a Key Opinion Leader event to highlight new clinical ... poster presentation at the upcoming 2017 ASCO-SITC Immuno-Oncology Symposium ... will be held in-person and via live webcast on ... AM PST at the Lotte New York Palace Hotel ...
(Date:2/23/2017)... SAN JOSE, Calif. , Feb. 23, 2017 ... an exclusive license for two key immunotherapy technologies ... The first technology provides a method to monitor ... therapy such as PD-L1 and CTLA-4.  The second ... detect if a patient is likely to have ...
(Date:2/23/2017)... ... February 23, 2017 , ... ... in a published evaluation of multiple immunoassay-based threat detection technologies by researchers ... Laboratory, PathSensors’ CANARY® biosensor threat detection technology was found to have the ...
(Date:2/23/2017)... 23, 2017 Aviva Systems Biology Corporation ... acquisition of GenWay Biotech Incorporated, a protein solutions ... product offering for both the research and diagnostic ... and enhance capabilities for both entities. GenWay,s 18 years ... will nicely complement ASB,s objective to become a ...
Breaking Biology Technology: