Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Powerful New Technique to Reveal Protein Function

21.06.2013
In the cover story for the journal Genetics this month, neurobiologist Dan Chase and colleagues at the University of Massachusetts Amherst describe a new experimental technique they developed that will allow scientists to study the function of individual proteins in individual cell types in a living organism.

The advance should allow deeper insights into protein function, Chase says, “because we can only get a true understanding of what that single protein does when we isolate its function in a living organism. There was no tool currently available to do this.”

The journal’s cover art uses a jigsaw puzzle of a worm to illustrate how knockdown strategies in this organism have evolved over time to achieve more and more cell-type specificity, culminating in the new approach developed by the Chase lab, which can restrict knockdown to a single cell type.

“This strategy is super cool and it works great,” he says. “We’ve already used it to tease apart some of the mechanisms of dopamine signaling, but the strategy can be adapted to study the function of any protein involved in any biological process.”

There are more than 1 trillion cells in the human body, yet only 20,000 to 25,000 genes are expressed in them, Chase explains, so each gene must be expressed in many different cells. Understanding the function of 20,000 genes and whether this differs by cell type has been difficult, but over the last 10 years, he adds, “we have learned that the answer to this last question is a resounding yes. Gene function can differ by cell type.”

Pursuing this further, however, was hampered by the fact that traditional approaches for studying protein function rely on genetic mutations that act on DNA, so they disrupt protein function in ALL cells. And to understand what a protein really does, it must be studied in an individual cell in a living organism.

Specifically, Chase’s lab uses the roundworm C. elegans to explore how dopamine modulates the activities of specialized neurons. The worm is a useful model because it has only 302 neurons instead of billions in mammals. Despite its simplicity, the worm’s basic neurotransmission mechanisms are also found in humans.

In the quest to identify genes that regulate dopamine signaling, the UMass Amherst researchers quickly recognized that dopamine acts through proteins used by other neurotransmitters in other nervous system cells. “So we couldn’t use traditional genetic tools to study dopamine signaling. We needed to develop a new method to study protein function in individual cells in multicellular organisms,” Chase notes.

The technique they developed takes advantage of nonsense-mediated decay (NMD), a surveillance mechanism present in all eukaryotic organisms. NMD destroys aberrant mRNA molecules that can arise naturally through mutation during transcription or mRNA processing.

“In our strategy, we replace the normal copy of a gene with a tagged version that targets the gene’s mRNA for destruction by NMD,” Chase explains. “We then remove NMD from all the organism’s cells. Without NMD present, the replacement gene is expressed normally in all cells. We then knock down expression of the gene cell-specifically by restoring NMD activity only in cells we select.”

He adds, “This cell-specific restoration of NMD activity is easy and can also be controlled in time. Thus, using NMD we can not only remove gene function in individual cell types, we can control exactly when gene function is removed in that cell type. This gives complete control of gene expression and allows one to investigate the function of any gene in any cell type at any time.”

“With this very powerful new technique, now you can identify an individual gene and you can ask whether it plays a role in the behavior of interest. All these genes are expressed in our brains, so we are learning about all sorts of fascinating interactions in the worm and we can begin to translate the meanings to humans. Dopamine signaling is something you really can’t study in the human brain very well, but with this approach we are having success.”

To measure how much RNA is left in the animals after NMD is activated, microbiologist Aishwarya Swaminathan in John Lopes’ group at UMass Amherst used quantitative polymerase chain reaction (PCR), an amplification technique, allowing the researchers to precisely measure the efficiency of the strategy.

Chase says, “It turns out that the NMD-mediated knockdown is super good, better than anything else available. And anybody can use it, it’s straightforward molecular biology.”

Daniel Chase | Newswise
Further information:
http://www.umass.edu

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>