A new strategy to analyze the cellular world

(Nanowerk News) In the past two decades, super-resolution microscopy has been one of the fastest evolving fields through many technical improvements. However, the development of new labeling tools, probes and their biological application, is mostly lagging behind the technical capabilities. Most recently, Prof. Silvio O. Rizzoli from the Cluster of Excellence and DFG- Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB) has developed together with his team a new technique that expands the benefit of super- resolution microscopy to study biological questions. This method contributes to understand on how cells renew, distribute and transport their molecular and subcellular components.
The new technique was published in the Journal of Cell Biology ("A new probe for super-resolution imaging of membranes elucidates trafficking pathways").
All cells rely on the recycling of membranes via various pathways (secretion, uptake, and membrane turnover). Several types of cellular organelles such as the plasma membrane, the endoplasmic reticulum, the Golgi apparatus, endosomes and vesicles are involved in these processes. However, it was difficult to identify the protein composition of the involved organelles since both, the membranes and the proteins of the same organelle need to be marked simultaneously. Here the main difficulty comes with the membrane probe, as almost all dyes that work excellent in live cell experiments are only poorly fixable and get “lost” during the antibody staining procedure.
The research team with first author Natalia Revelo therefore developed a membrane probe that overcomes this problem. The probe mCLING (membrane-binding fluorophore-Cysteine- Lysine-Palmitoyl Group) is a composition of a short polypeptide coupled to a membrane anchor and a fluorophore.
The study, recently published in the Journal of Cell Biology, shows that mCLING can be used to label the plasma membrane, and also to faithfully track specific organelles, which can be done in conjunction with fixation and immunostaining, in both cell culture and in tissue. The utility of the mCLING probe could be characterized for various important biological model systems and already enabled the authors to answer long-lasting?question in the field of membrane recycling.
Moreover, mCLING imaging could also be extended to different processes. For example, the structure and molecular organization of isolated organelles in vitro, or the arrangement of proteins on the membranes of various types of cells, can be easily tackled with mCLING. These efforts will be aided by the fact that mCLING can be optimized for any available super-resolution technique.
Prof. Dr. Silvio O. Rizzoli is head of the Department of Neuro- and Sensory Physiology at the University Medical Center Göttingen and member of the Göttingen Cluster of Excellence and DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB). His research focus includes the identification of molecular signal transduction processes between nerve cells. Prof. Rizzoli applies super-resolution microscopy techniques to study the transport and function of intracellular vesicles in the synapses of nerve cells. Very recently, Prof. Rizzoli received for the second time with a prestigious funding award of the European Union for his excellent research proposal.
Source: Cluster of Excellence and DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain