In order to investigate the potential role of these motifs in the viral life cycle, we have undertaken a detailed mutagenic analysis of these proline residues in the context of both genotype 1b (FK5.1) or 2a subgenomic replicons and the genotype 2a infectious clone, JFH-1. We show that the PP2.2 motif is dispensable for RNA replication of all subgenomic replicons and, furthermore, is not required for virus production in JFH-1. In contrast, the PP2.1 motif is only required for genotype 1b RNA replication. Mutation

of proline 346 within PP2.1 to alanine see more dramatically attenuated genotype 1b replicon replication in three distinct genetic backgrounds, but the corresponding proline 342 was not required for replication of the JFH-1 subgenomic replicon. However, the P342A mutation resulted in both a delay to virus release and a modest (up to 10-fold) reduction in virus production. These data point to critical roles for these proline residues at multiple stages in the HCV life cycle; however, they

also caution against extrapolation of data from culture-adapted check details replicons to infectious virus.”
“Previous reports suggest that gamma-aminobutyric acid type A (GABA(A)) receptors containing alpha 1 subunits may play a pivotal role in mediating the discriminative stimulus effects of benzodiazepines (BZs). L-838,417 (7-tert-Butyl-3-(2,5-difluoro-phenyl)-6-(2-methyl-2H-[1,2,4]triazol-3-ylmethoxy)-[ 1,2,4]triazolo[4,3-b]pyridazine) is a GABA(A) receptor modulator with intrinsic efficacy in vitro at alpha 2, alpha 3, and alpha 5 subunit-containing GABA(A) receptors, and little demonstrable intrinsic efficacy in vitro at alpha 1 subunit-containing GABA(A) receptors. Glycogen branching enzyme The present study evaluated the discriminative stimulus effects of L-838,417 in order to determine the extent to which the alpha 2, alpha 3, and alpha 5 subunit-containing

GABA(A) receptors contribute to the interoceptive effects of BZ-type drugs. Squirrel monkeys (Saimiri sciureus) were trained to discriminate L-838,417 (0.3 mg/kg. i.v.) from vehicle under a 5-response fixed-ratio schedule of food reinforcement. Under test conditions, L-838,417 administration resulted in dose-dependent increases in drug-lever responding that were antagonized by the BZ-site antagonist, flumazenil. Administration of non-selective BZs, compounds with 10-fold greater affinity for alpha 1 subunit-containing GABA(A) receptors compared to alpha 2, alpha 3, and alpha 5 subunit-containing GABA(A) receptors, barbiturates and ethanol (which modulate the GABA(A) receptor via a non-BZ site), all resulted in a majority of responses on the L-838,417-paired lever (65-100% drug-lever responding).