New technique detects how proteins undergo changes inside a cell

In the September issue of Molecular & Cellular Proteomics, scientists describe a new technique that can detect how proteins undergo changes inside a cell.

The technique promises to improve our understanding of how proteins inside cells work and identify how some proteins are not modified properly in common diseases such as cancer and cardiovascular diseases.

In 2006, Ola Soderberg and colleagues established a technique called in situ proximity ligation assay (in situ PLA) to reveal protein-protein interactions in cells. The technique recognizes a target protein by binding a “probe” consisting of a pair of proteins attached to DNA onto the target protein. Then the DNA is replicated, producing a molecule that can be visualized under a microscope as a fluorescent spot – thus marking the presence of individual molecules in the target protein.

In the new study, Soderberg and colleagues developed a generalized version of the technique in which different probes can identify proteins that have undergone various changes in their structure. The researchers used this technique to detect a protein on the membrane of cells called platelet-derived growth factor receptor beta, which undergoes changes that will promote cell proliferation and movement. The technique is more sensitive and selective than other currently-used techniques, that is, it does not miss as many proteins as the other techniques do and the rate of mix-ups among the detected proteins is lower.

Article: “ In Situ Detection of Phosphorylated Platelet-derived Growth Factor Receptor Beta Using a Generalized Proximity Ligation Method,” by Malin Jarvius, Janna Paulsson, Irene Weibrecht, Karl-Johan Leuchowius, Ann-Catrin Andersson, Carolina Wahlby, Mats Gullberg, Johan Botling, Tobias Sjoblom, Boyka Markova, Arne Ostman, Ulf Landegren, and Ola Soderberg

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