Lateral Diffusion in Heterogeneous Cell Membranes

Role of Actin Cytoskeleton in Dynamics and Function of the Serotonin1A Receptor

“…Interestingly, the diffusion coefficient values obtained from our SPT measurements are much lower than the corresponding value obtained using z-scanning fluorescence correlation spectroscopy ($4 mm 2 s À1 ) (50). The difference in the magnitude of diffusion coefficients of the serotonin 1A receptor obtained by these techniques could be attributed to the varying spatiotemporal resolutions associated with these approaches (42,70,71). SPT and FCS represent two different approaches for observing diffusion behavior.…”

“…Measurement of membrane dynamics could be challenging because of inherent noise in cellular systems. Nonetheless, significant progress has been made in recent years toward the measurement of membrane dynamics that allows the detection, identification, and tracking of individual membrane-bound molecules with high spatiotemporal resolution under physiological conditions (39)(40)(41)(42). A major advantage of imaging single-molecule diffusion is that it circumvents ensemble averaging from multiple molecules.…”

“…As a result, single-molecule based approaches enable observation of heterogeneous behavior (and transient phe-nomena) within subpopulations of molecules (43). Singlemolecule techniques such as single particle tracking (SPT) have emerged as a powerful approach to explore the organization and lateral diffusion of membrane-bound molecules (31,42,44,45). Although SPT has been used to probe dynamics of membrane-bound molecules (39,46), the application of SPT to GPCRs is relatively rare (47,48).…”

How to best estimate the viscosity of lipid bilayers

“…Beyond resolving the latter controversy, our results bear biological significance because modulation of hydrophobic mismatch and local membrane deformation [72], lateral organization [73], curvature [74] or membrane viscosity critically modulate the function of membrane proteins. A most recent and relevant example, is the case of rhomboid intramembrane proteases.…”

Cholesterol-Dependent Dynamics of the Serotonin1A Receptor Utilizing Single Particle Tracking: Analysis of Diffusion Modes

“…A variety of microscopy-based techniques have been established to measure diffusion in heterogeneous biological membranes. The widely used approaches to probe lateral dynamics in membranes are fluorescence recovery after photobleaching (FRAP), fluorescence correlation spectroscopy (FCS), and single particle tracking (SPT). ,− In recent years, significant progress has been made toward the measurement and interpretation of membrane dynamics at the single-molecule level that helps detection and tracking of individual membrane-bound molecules under physiological conditions with a high spatiotemporal resolution. − The advantage of single-molecule measurement is that it allows to circumvent ensemble averaging from multiple molecules, thereby providing information about the heterogeneous behavior (and transient phenomena) within subpopulations of molecules …”