Use of Kikume green-red fusions to study the influence of pharmacological chaperones on trafficking of G protein-coupled receptors.

In this study we demonstrate that the photoconvertible monomeric Kikume green-red (mKikGR) protein is suitable to study trafficking of G protein-coupled receptors. Taking mKikGR-tagged mutants of the vasopressin V(2) receptor (V(2)R) as models, we analyzed whether the V(2)R-specific pharmacological chaperone SR121463B influences receptor folding on a co- or post-translational level. Misfolded mKikGR-tagged V(2)Rs were completely photoconverted in the early secretory pathway yielding a red receptor population (already synthesized receptors) and an arising green receptor population (newly synthesized receptors).

Inhibition of biosynthesis of human endothelin B receptor by the cyclodepsipeptide cotransin.

The specific inhibition of the biosynthesis of target proteins is a relatively novel strategy in pharmacology and is based mainly on antisense approaches (e.g. antisense oligonucleotides or RNA interference).

The pseudo signal peptide of the corticotropin-releasing factor receptor type 2a decreases receptor expression and prevents Gi-mediated inhibition of adenylyl cyclase activity.

The corticotropin-releasing factor receptor type 2a (CRF(2(a))R) belongs to the family of G protein-coupled receptors. The receptor possesses an N-terminal pseudo signal peptide that is unable to mediate targeting of the nascent chain to the endoplasmic reticulum membrane during early receptor biogenesis. The pseudo signal peptide remains uncleaved and consequently forms an additional hydrophobic receptor domain with unknown function that is unique within the large G protein-coupled receptor protein family.

Nanomechanical characterization of phospholipid bilayer islands on flat and porous substrates: a force spectroscopy study.

In this study, we compare for the first time the nanomechanical properties of lipid bilayer islands on flat and porous surfaces. 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) bilayers were deposited on flat (silicon and mica) and porous silicon (pSi) substrate surfaces and examined using atomic force spectroscopy and force volume imaging. Force spectroscopy measurements revealed the effects of the underlying substrate and of the lipid phase on the nanomechanical properties of bilayers islands.

Regional distribution of the prostaglandin E2 receptor EP1 in the rat brain: accumulation in Purkinje cells of the cerebellum.

Prostaglandin E2 (PGE2), is a major prostanoid produced by the activity of cyclooxygenases (COX) in response to various physiological and pathological stimuli. PGE2 exerts its effects by activating four specific E-type prostanoid receptors (EP1, EP2, EP3, and EP4). In the present study, we analyzed the expression of the PGE2 receptor EP1 (mRNA and protein) in different regions of the adult rat brain (hippocampus, hypothalamus, striatum, prefrontal cerebral cortex, parietal cortex, brain stem, and cerebellum) using reverse transcription- polymerase chain reaction, Western blotting, and immunohistochemical methods.