Publications in Scientific Journals:
A. Anderluh, E. Klotzsch, J. Ries, A. Reismann, S. Weber, M. Fölser, F. Koban, M. Freissmuth, H. Sitte, G. Schütz:
"Tracking Single Serotonin Transporter Molecules at the Endoplasmic Reticulum and Plasma Membrane";
Transmembrane proteins are synthesized and folded in the endoplasmic reticulum (ER), an interconnected
network of flattened sacs or tubes. Up to now, this organelle has eluded a detailed analysis of the dynamics of its constituents,
mainly due to the complex three-dimensional morphology within the cellular cytosol, which precluded high-resolution, single-molecule
microscopy approaches. Recent evidences, however, pointed out that there are multiple interaction sites betweenERand the
plasma membrane, rendering total internal reflection microscopy of plasma membrane proximal ER regions feasible. Here we
used single-molecule fluorescence microscopy to study the diffusion of the human serotonin transporter at the ER and the plasma
membrane. We exploited the single-molecule trajectories to map out the structure of the ER close to the plasma membrane at
subdiffractive resolution. Furthermore, our study provides a comparative picture of the diffusional behavior in both environments.
Under unperturbed conditions, the majority of proteins showed similar mobility in the two compartments; at the ER, however, we
found an additional 15% fraction of molecules moving with 25-fold faster mobility. Upon degradation of the actin skeleton, the diffusional
behavior in the plasma membrane was strongly influenced, whereas it remained unchanged in the ER.
Created from the Publication Database of the Vienna University of Technology.