Measuring protein-membrane interaction through radial fluorescence correlation in 2 dimensions.

The cell membrane has a fundamental role in the cell life cycle but there's
still much to be learned about its heterogeneous structure, regulation, and protein interaction.
Additionally, the protein-membrane interaction is often overlooked when studying specific protein
dynamics. In this work, we present a new tool for a better understanding of protein dynamics
and membrane function using live cells and fast non-invasive techniques without the need for
individual particle tracking. To this end, we used the 2D-pair correlation function (2D-pCF) to
study protein interactions across cellular membranes. We performed numerical simulations and
confocal experiments using a GAP-mEGFP fusion construct known to interact with the plasmatic
membrane. Our results demonstrate that based on a quantitative correlation analysis as the 2D
pair correlation of the signal intensities, is possible to characterize protein-membrane interactions
in live systems and real-time. Combining experimental and numerical results this work presents
a new powerful approach to the study of the dynamic protein-membrane interaction.