Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Malaria parasite packs genetic material for trip from mosquitoes to humans

11.01.2018

Have RNA, will travel

The parasite that causes malaria has not one, but two, specialized proteins that protect its messenger RNAs -- genetic material that encodes for proteins -- until the parasite takes up residence in a new mosquito or a human host. A new study by researchers at Penn State describes the two proteins and reveals an additional role that one may play to facilitate RNA-based interactions between the parasite, its mosquito vector, and its human host. The study appears January 10, 2018, in the journal mSphere.


Because the malaria parasite Plasmodium cannot anticipate when it may be transmitted from a mosquito to a mammalian host, it uses specialized poly(A)-binding proteins to package and protect its genetic material for use after transmission.

Credit: Centers for Disease Control and Prevention

"Understanding the malaria parasite and how it interacts with its host may provide insights that could help prevent the spread of this often-fatal disease," said Scott Lindner, assistant professor of biochemistry and molecular biology at Penn State and senior author of the study. "The malaria parasite has a complex life cycle that includes phases in the mosquito vector, the human liver, and in human blood. Moreover, the parasite has no idea when it's going to be transmitted from a mosquito to a human host and back, so it always needs to be ready to be transmitted. It prepares for this by making and packaging up the mRNAs that it will eventually need for making proteins inside its new host or a new mosquito."

During this process, called translational repression, special proteins bind to mRNAs and prevent them from being translated into protein. One protein involved binds to the mRNA's poly(A) tail -- a repeated string of As or adenosine molecules added to the end of most mRNA strands. This helps to form a complex of proteins and RNA that is silenced but poised for action after the parasite is transmitted to the host. Most single-celled organisms have one type of this poly(A)-binding protein, while multi-cellular organisms have two. In this study, the researchers characterize two types of poly(A)-binding proteins in the single-celled Plasmodium parasite, both of which contribute to translational regulation.

"We knew from our lab's previous work that Plasmodium had a type of poly(A)-binding protein that functions outside of the nucleus of the cell," said Allen Minns, research technician at Penn State and first author of the paper. "This protein binds and protects the poly(A) tail at one end of an mRNA strand. In this study, we used biochemical approaches to further characterize this protein, and found that it also has a specialized job receiving mRNAs. It forms chains without the presence of RNA, which potentially allows large assemblies of the protein to quickly protect the entire length of the poly(A) tail."

The researchers also identified and characterized a second type of poly(A)-binding protein that functions inside the nucleus of the parasite during the blood stages of its life cycle. In multi-cellular organisms, this second poly(A)-binding protein usually performs a quality control check before mRNA exits the nucleus, confirming that the mRNA is constructed properly. These quality control proteins then pass on the mRNA strand to other proteins outside of the nucleus, which direct the mRNA to be translated or to be packaged for later use through translational repression.

In addition to an important role in translational regulation inside of the cell, the researchers also discovered that the non-nuclear poly(A)-binding protein may play a surprising role outside of the cell.

"When the parasite takes the form of a sporozoite in the mosquito, we actually don't see the vast majority of the non-nuclear poly(A)-binding protein inside the cell where we expected it to be -- where it would interact with mRNAs produced by the parasite," said Lindner. "Instead, the protein accumulates at the surface of the sporozoite and is shed when the parasite moves. We don't see this happening in other life stages of the parasite, and this is now the third RNA-binding protein found to be on the surface of the sporozoite. The parasite is putting these RNA-binding proteins out there on its surface for a reason; the new and exciting question is why."

The researchers speculate that the poly(A)-binding proteins on the sporozoite surface allow the parasite to interact with RNA from sources outside of the parasite and could thus provide an opportunity for the parasite to interact with the mosquito or the host through their RNA.

"This study suggests that the parasite's interaction with outside RNA is probably much more pervasive than we thought it was," said Lindner. "It is possible that this kind of interaction could eventually provide a new target for intervention strategies, but the first step is understanding why the malaria parasite has these poly(A)-binding proteins on the sporozoite surface."

###

In addition to Lindner and Minns, the research team includes Penn State graduate students Kevin Hart and Suriyasri Subramanian, and Susan Hafenstein, associate professor of biochemistry and molecular biology at Penn State and associate professor of at Penn State University Park, and associate professor medicine and of microbiology and immunology at the Penn State College of Medicine. This work was funded by the National Institutes of Health and supported by the Huck Institutes of the Life Sciences.

Media Contact

Barbara Kennedy
BarbaraKennedy@psu.edu
814-863-4682

 @penn_state

http://live.psu.edu

Barbara Kennedy | EurekAlert!

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

NSF-supported researchers to present new results on hurricanes and other extreme events

19.07.2018 | Earth Sciences

Scientists uncover the role of a protein in production & survival of myelin-forming cells

19.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>