AUG 29, 2016 01:04 PM PDT

Refining the Principles of Protein Translation

WRITTEN BY: Carmen Leitch
2 8 589
It’s long been accepted that when proteins are made in the cell, a messenger RNA molecule made using DNA as a template sends instructions to the ribosome, a cellular organelle that acts as a protein factory. When the cellular machinery of the body is working normally, the newly created protein goes from a string of amino acids to a folded structure with a very specific conformation. If you need a refresher on this process, check out the video below. 

When those processes are dysfunctional, diseases like cancer and neurodegenerative disorders can result. A thorough understanding of the mechanisms of protein translation could help researchers develop effective therapies and treatments for those diseases.

In the early 70s, scientists learned that there is a signal, was called the signal recognition particle (SRP), on the initial part of many proteins that causes the ribosome to move the newly made protein into an organelle in the cell called the endoplasmic reticulum. That finding was the basis for future research that led to the award of the 1999 Nobel Prize in Physiology or Medicine.  It was thought that the SRP helps guide the protein to the ER, while also temporarily stopping the production of more proteins. Once the protein gets to the ER, the protein production begins again. However, new data has challenged those old paradigms.
Micrograph of rough endoplasmic reticulum network around the nucleus (shown in lower right-hand side of the picture). Dark small circles in the network are mitochondria. / Credit: Louisa Howard, Dartmouth
"Our data supported the role for SRP, but our experiments did not support this model," explained Judith Frydman, a Professor of Biology and of Genetics at Stanford University.

"This is what is so cool about this study. We found that in fact SRP works through a very different and completely unexpected mechanism." Frydman and her team discovered that messenger RNA actually has a small piece of information the SRP recognizes prior to the start of protein production. Before the protein even emerges, the SRP hangs out where the protein exits the ribosome.

"It's almost prescient; it already knows before it comes and just steps right in," Frydman said. Additionally, the researchers found that the SRP actually doesn’t stop the production of proteins at all, contrary to previous belief. Their discoveries have important implications for disease research.

Frydman explained that many crucial processes are dependent on the reliable and proper movement of proteins. If a protein gets stuck in the cytoplasm where it should not be, it may build up and lead to unwanted consequences simply from the loss of the normal function of the protein, or from a new and unintended function because of the aggregation.

"Many proteins that are important pharmaceutically are made in large part by targeting them to this secretory pathway," Frydman said. "But they have also been designed relying on this classical model. Having a better understanding of this process could really enhance the process of designing new pharmaceuticals."

Sources: via Stanford University, Nature
About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JUN 08, 2018
JUN 08, 2018
Interfering with Inflammatory Signals to Treat Arrhythmia
Part of the immune system has now been implicated in the development of atrial fibrillation (AF), the most common heart arrhythmia that leads to stroke, bl
JUN 21, 2018
JUN 21, 2018
The World's First In Utero Stem Cell Transplant
Stem cells were harvested from a mother and successfully transplanted into her growing fetus.
JUN 27, 2018
Cell & Molecular Biology
JUN 27, 2018
Finding a new way to Stop the Growth of Cancer
Scientists discovered something new about the behavior of an organelle called ribosomes in cancer cells.
JUL 22, 2018
Cell & Molecular Biology
JUL 22, 2018
Using Nanosubmarines to Fight Tumors and Headaches
Researchers are getting closer to creating targeted therapies that are delivered directly where needed.
JUL 29, 2018
JUL 29, 2018
Revealing why Sepsis Causes Organs to Fail
The Staphylococcus aureus bacterium can cause devastating illnesses - called staph infections - and lead to organ failure.
AUG 05, 2018
Genetics & Genomics
AUG 05, 2018
Newly ID'ed Lung Cell Changes Our Understanding of Disease
This rare type of cell seems to play a major role in cystic fibrosis.
Loading Comments...