Image mean square displacement to study the lateral mobility of Angiotensin II type 1 and Endothelin 1 type A receptors on living cells.

The lateral mobility of membrane receptors provides insights into the molecular interactions of protein binding and the complex dynamic plasma membrane. The image mean square displacement (iMSD) analysis is a method used to extract qualitative and quantitative information of the protein diffusion law and infers how diffusion dynamic processes may change when the cellular environment is modified. The aim of the study was to describe the membrane diffusing properties of two G-protein-coupled receptors namely Angiotensin II type 1 (AT ) and Endothelin 1 type A (ET ) receptors and their corresponding receptor-ligand complexes in living cells using total internal reflection fluorescent microscopy and iMSD analysis.

Number and brightness analysis to study spatio-temporal distribution of the angiotensin II AT and the endothelin-1 ET receptors: Influence of ligand binding.

The angiotensin II AT and the endothelin 1 ET receptors play a crucial role in the pathogenesis of cardiovascular diseases like hypertension, heart failure, stroke, pulmonary hypertension, and cardiac hypertrophy. Both receptors are members of the rhodopsion-like superfamily of G protein-coupled receptors which can exist as monomers, dimers, and higher order aggregates. Recently, oligomerization of these two receptors have been described by several biophysical methods based mainly on luminescence and fluorescence energy transfer.