Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Technique Maps Elusive Chemical Markers on Proteins

03.07.2015

Unveiling how the 20,000 or so proteins in the human body work—and malfunction—is the key to understanding much of health and disease. Now, Salk researchers developed a new technique that allows scientists to better understand an elusive step critical in protein formation.

The new method, described on July 2, 2015 in the journal Cell, allows researchers to map critical chemical tags—called phosphates—that bond to amino acids (the building blocks of proteins) in the final stages of creating a protein.


Salk Institute

Caption: Salk scientists developed antibodies that tag essential chemicals involved in protein action. In this dividing cell, the new antibody (green) marks discrete areas of a critical but elusive chemical reaction that happens when cells divide (DNA in blue and tubulin, a protein needed for cell division, in red).

When a cell produces a protein, molecular synthetic machinery first pieces together the amino acids into a long strand that bends and folds as it lengthens. Enzymes then gather around the structure to make final tweaks—trimming the protein or adding chemical tags. Among these last modifications is phosphorylation—or addition of phosphate—of individual amino acids to change the protein’s function. Until now, pinpointing exactly where (and why) all those phosphates are added has been tricky.

“We know that 9 out of the 20 amino acids can be phosphorylated, but we know very little about most of them because they’re so hard to study,” says Tony Hunter, American Cancer Society Professor, holder of the Dulbecco Chair in the Salk’s Molecular and Cell Biology Laboratory and senior author of the new paper.

When phosphate is added to three particular amino acids—serine, threonine and tyrosine—it forms a strong chemical bond. Researchers can easily identify the location of these phosphates. But when the other six amino acids are phosphorylated, the phosphate is only loosely attached to each amino acid, causing problems for researchers trying to glean what happens in these cases. One of these amino acids, called histidine (or phosphohistidine once a phosphate is added), has been particularly tough to study.

“With those strong phosphorylation events, you can label cells, isolate proteins and analyze the proteins in various ways to find out where the phosphates are,” says Hunter. “You can’t do that with phosphohistidine because it’s so unstable it falls apart as you’re trying to isolate the proteins.”

Hunter and his collaborators realized that to study this unstable interaction, they would have to use a trick to make a stronger bond between phosphate and histidine. So they used a special kind of modified phosphate, called phosphonate, engineered to bind more tightly to either of the two spots on a histidine amino acid where phosphate can be added. Then, they developed antibodies that specifically recognize these stable phosphohistidine analogues, but also detect authentic phosphohistidine in proteins.

To test these new tools, the team added their phosphohistidine antibodies to a collection of different mammalian cells grown on slides and observed where in the cell the antibodies bound, which indicates parts of cells that have high levels of proteins with phosphohistidines.

“The thing that surprised us most is that when we stained the cells with the new antibodies, we saw discrete areas within the cells that had high levels of histidine phosphorylation, particularly when they were undergoing mitosis, the stage at which cells divide into two daughter cells,” says Hunter. They don’t yet know exactly why that is, but plan to continue to explore these results as well as detect the phosphorylation of other amino acids.

The team expects these antibody tools to be useful to other labs aiming to determine whether proteins of interest have any phosphohistidines.

The new method is “fairly easy for any lab to use,” Hunter says. “It doesn’t require a special instrument or anything, so I think it may be fairly quickly adopted.”

Other researchers on the study were Stephen Rush Fuhs, Jill Meisenhelder, Aaron Aslanian, Li Ma, Anna Zagorska and Greg Lemke, of the Salk Institute; Magda Stankova, Alan Binnie, Fahad Al-Obeidi and Jacques Mauger, of Sanofi; and John R. Yates III of the Scripps Research Institute.

The work and the researchers involved were supported by the National Institutes of Health, a Salk Institute Innovation Grant and the Helmsley Center for Genomic Medicine.

About the Salk Institute for Biological Studies:
The Salk Institute for Biological Studies is one of the world's preeminent basic research institutions, where internationally renowned faculty probes fundamental life science questions in a unique, collaborative and creative environment. Focused both on discovery and on mentoring future generations of researchers, Salk scientists make groundbreaking contributions to our understanding of cancer, aging, Alzheimer's, diabetes and infectious diseases by studying neuroscience, genetics, cell and plant biology, and related disciplines. Faculty achievements have been recognized with numerous honors, including Nobel Prizes and memberships in the National Academy of Sciences. Founded in 1960 by polio vaccine pioneer Jonas Salk, MD, the Institute is an independent nonprofit organization and architectural landmark.

Contact Information
Salk Communications
press@salk.edu

Salk Communications | newswise
Further information:
http://www.salk.edu

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>