The modifications induced by hypericin on the electric properties of the artificial lipid bilayers suggest that it has apparent stabilizing effects on the membrane against strong chaotropic anions. We imply that this is due to the interference of hypericin’s insertion into the bilayers with the mechanisms by which the lyotropic anions alter the electrical surroundings of the bilayer and/or the ...

The establishment and maintenance of the polarized epithelial phenotype require a characteristic organization of the cytoskeletal components. There are many cellular effectors involved in the regulation of the cytoskeleton of epithelial cells. Recently, modifications in the plasma membrane potential (PMP) have been suggested to participate in the modulation of the cytoskeletal organization of e...

During and after their synthesis, the envelope proteins of influenza viruses are extensively modified by glycosylation, disulfide-bond formation, oligomerisation and proteolytical cleavage. These modifications have an enormous impact on folding and transport of the proteins to the plasma membrane and are also crucial for the infectivity and pathogenicity of the resulting virus particles. Here w...

Membrane proteins frequently assemble into higher order homo- or hetero-oligomers within their natural lipid environment. This complex formation can modulate their folding, activity as well as substrate selectivity. Non-disruptive methods avoiding critical steps, such as membrane disintegration, transfer into artificial environments or chemical modifications are therefore essential to analyze m...

Diffusion-time distribution analysis (DDA) has been used to explore the plasma membrane fluidity of multidrug-resistant cancer cells (LR73 carcinoma cells) and also to characterize the influence of various membrane agents present in the extracellular medium. DDA is a recent single-molecule technique, based on fluorescence correlation spectroscopy (FCS), well suited to retrieve local organizatio...

The decreased efficiency of immune responses in older people is partly a consequence of alterations in T lymphocyte functions caused by modifications in the early events of signal transduction. Several alterations in the signaling pathways of T lymphocytes have been described in older humans and animals. A unifying cause could be modifications in the physicochemical properties of the plasma mem...

Long-term information storage within the brain requires the synthesis of new proteins and their use in synapse-specific modifications [1]. Recently, we demonstrated that translation sites for the local synthesis of integral membrane and secretory proteins occur within distal dendritic spines [2]. It remains unresolved, however, whether a complete secretory pathway, including Golgi and trans Gol...

The cellular functions of many eukaryotic membrane proteins, including the vasopressin-regulated water channel aquaporin-2 (AQP2), are regulated by posttranslational modifications. In this article, we discuss the experimental discoveries that have advanced our understanding of how posttranslational modifications affect AQP2 function, especially as they relate to the role of AQP2 in the kidney. ...

S-palmitoylation is post-translational modification, which consists in the addition of a C16 acyl chain to cytosolic cysteines and which is unique amongst lipid modifications in that it is reversible. It can thus, like phosphorylation or ubiquitination, act as a switch. While palmitoylation of soluble proteins allows them to interact with membranes, the consequences of palmitoylation for transm...