The dynamin-dependent, arrestin-independent internalization of 5-hydroxytryptamine 2A (5-HT2A) serotonin receptors reveals differential sorting of arrestins and 5-HT2A receptors during endocytosis.
'5-Hydroxytryptamine 2A (5-HT2A) receptors, a major site of action of clozapine and other atypical antipsychotic medications, are, paradoxically, internalized in vitro and in vivo by antagonists and agonists. The mechanisms responsible for this paradoxical regulation of 5-HT2A receptors are unknown. In this study, the arrestin and dynamin dependences of agonist- ... More
Real experiences of uHTS: a prototypic 1536-well fluorescence anisotropy-based uHTS screen and application of well-level quality control procedures.
AuthorsTurconi S, Shea K, Ashman S, Fantom K, Earnshaw DL, Bingham RP, Haupts UM, Brown MJ, Pope AJ
JournalJ Biomol Screen
PubMed ID11689128
This paper describes, for the first time, a true ultra-high throughput screen (uHTS) based upon fluorescence anisotropy and performed entirely in 1536-well assay plates. The assay is based upon binding and displacement of a BODIPY-FL-labeled antibiotic to a specific binding site on 70S ribosomes from Escherichia coli (Kd approximately 15 ... More
Donor-donor energy migration (DDEM) as a tool for studying aggregation in lipid phases.
AuthorsMikhalyov I, Bogen ST, Johansson LB
JournalSpectrochim Acta A Mol Biomol Spectrosc
PubMed ID11506035
A BODIPY-labelled sulfatide (N-(BODIPY-FL-pentanoyl)-galactosylcerebroside-sulfate, hereafter abbreviated as BD-Sulfatide) was solubilised at different concentrations in lipid vesicles of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). Time-correlated single photon counting experiments show that the fluorescence relaxation is mono-exponential (with a lifetime of 6.5 ns) at molar ratios of BD-Sulfatide: DOPC that are less than 1:100. The fluorescence ... More
Different sphingolipids show differential partitioning into sphingolipid/cholesterol-rich domains in lipid bilayers.
AuthorsWang TY, Silvius JR
JournalBiophys J
PubMed ID10969009
Two fluorescence-based approaches have been applied to examine the differential partitioning of fluorescent phospho- and sphingolipid molecules into sphingolipid-enriched domains modeling membrane "lipid rafts." Fluorescence-quenching measurements reveal that N-(diphenylhexatrienyl)propionyl- (DPH3:0-)-labeled gluco- and galactocerebroside partition into sphingolipid-enriched domains in sphingolipid/phosphatidylcholine/cholesterol bilayers with substantially higher affinity than do analogous sphingomyelin, ceramide, or ... More
Functional characterization of coding polymorphisms in the human MDR1 gene using a vaccinia virus expression system.
AuthorsKimchi-Sarfaty C, Gribar JJ, Gottesman MM
JournalMol Pharmacol
PubMed ID12065748
The human MDR1-encoded transporter is a 170-kDa plasma membrane glycoprotein [P-glycoprotein (P-gp)] capable of binding and energy-dependent extrusion of structurally diverse organic compounds and drugs. P-gp seems to play a significant role in uptake, distribution, and excretion of many different drugs. To determine whether common polymorphic forms of P-gp are ... More