Chloroplasts can cut an interrupting insertion from a protein, but only in the light
A new way of fixing inactive proteins has been discovered in an algae, which uses chloroplast extracts and light to release an interrupting sequence from a protein.
Research specialist Stephen Campbell and Professor David Stern at the Boyce Thompson Institute report the discovery in the July 29 issue of the Journal of Biological Chemistry. This repair system may have applications in agriculture and biotechnology because it could potentially be harnessed to enable proteins to become active only in the light.
Many proteins contain extra sequences, called insertions, that can disrupt their function. The current paper demonstrates that the algae Chlamydomonas reinhardtii has the necessary toolkit to repair proteins by removing these insertions.
Campbell discovered this new repair system while purifying a protein from the chloroplasts of C. reinhardtii that can cut RNA. Upon sequencing the protein, he identified it as RB47, a protein that was not known to have any RNA-cleaving ability. Campbell noticed that the middle of the protein was missing. When he compared the protein sequence to its corresponding gene sequence, the protein was much shorter than expected.
Upon further study, Campbell found that he could detect a long version of the protein that contained an insertion and a short version that didn't. The cells make both versions when grown in the light or the dark, but only the short version can cleave RNA. The long version of the protein could be converted into the short one by mixing it in a test tube with chloroplasts from cells grown in the light and by illuminating the reaction. This process removed the interrupting insertion and restored the RNA-cutting activity of the protein. It is likely that the chloroplast maintains the machinery necessary to remove the sequence so that it can restore functionality to the protein.
This new type of repair system provides intriguing possibilities for biotech applications.
Because the insertion can be placed so that it interrupts a protein's function, the insertion and repair system may be useful for producing certain pharmaceuticals or protein products--such as cancer drugs--in culture, which would otherwise kill the cell. After purification, the inactive products could be treated with chloroplast factors and light to remove the insertion and activate the proteins.
In future work, the researchers plan to investigate exactly how the insertion becomes spliced out of the protein and which plant factors facilitate its removal. They also aim to understand the purpose of the insertion, and whether the algae can control the splicing to respond to changes in the environment.
Campbell and Stern also want to know how widespread this new type of protein splicing might be.
"If it is happening in plants, is it happening in animals?" said Stern. "We're pretty sure that this protein is just one example; that we have only found the tip of the iceberg."
The study was supported by the U.S. National Science Foundation, award MCB-1244106.
Boyce Thompson Institute
533 Tower Road
Ithaca, New York 14853 USA
To learn more about Boyce Thompson Institute (BTI) research, visit the BTI website at http://bti.
About Boyce Thompson Institute
Boyce Thompson Institute is a premier life sciences research institution located in Ithaca, New York on the Cornell University campus. BTI scientists conduct investigations into fundamental plant and life sciences research with the goals of increasing food security, improving environmental sustainability in agriculture and making basic discoveries that will enhance human health.
BTI employs 150 staff, with scientists from 40 countries around the world and has twice been named as one of the Best Companies in New York State. Its 15 principal investigators are leading minds in plant development, chemical ecology, microbiology and plant pathology, and have access to the institute's state-of-the-art greenhouse facilities with computerized controls and a system of integrated pest management. BTI has one of the largest concentrations of plant bioinformaticists in the U.S., with researchers who work across the entire spectrum of "omics" fields. BTI researchers consistently receive funding from NSF, NIH, USDA and DOE and publish in top tier journals. Throughout its work, BTI is committed to inspiring and educating students and to providing advanced training for the next generation of scientists. For more information, visit http://www.
Patricia Waldron | EurekAlert!
New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy