Imaging of insulin receptors in the plasma membrane of cells using superresolution single molecule localization microscopy
Abstract
The spatial organization of plasma membrane proteins such as the insulin receptor (IR) and the insulin-like growth factor receptor (IGF1R) reflect their functional relationships. In particular, the clustering or aggregation of plasma membrane proteins involved in cellular signaling is an important mechanism of cellular regulation and has long been a topic of research.
Efforts to elucidate the functional relationships and the dynamic state of organization of plasma membrane molecules have historically relied on classical biochemical assays and on measurements of intermolecular interactions using methods such as fluorescence resonance energy transfer (FRET). However, using recently developed superresolution imaging methods such as single molecule localization microscopy (SMLM), we can now directly image the organization of receptors in the plasma membrane with a resolution of ~20 nm.
With this data we can estimate parameters such as receptor number and density. We can also evaluate phenomena such as receptor clustering directly and efficiently.
Here we present our preliminary data, imaging methods, and evaluation approaches for visualization of IR in the plasma membrane of rat basophilic leukemia (RBL)-2H3 cells.