Thus, dominance arises from preferential endoproteolytic nicking between stable segments followed by loading of fragment terminal regions into antigen-presenting proteins. This mechanism probably arose in order to direct CD4(+) responses onto sequences that are conserved for structure and function. Structure-guided presentation could enhance protection against genetically drifting influenza virus variants but Selleckchem OTX015 most likely reduces protection against new viral subtypes.”
“We have previously demonstrated that alpha-synuclein (Snca) gene ablation reduces brain arachidonic acid (20:4n – 6) turnover rate in phospholipids
through modulation of endoplasmic reticulum-localized acyl-CoA synthetase activity. Although 20:4n – 6 is a precursor for prostaglandin (PG), Snca effect on PG levels is unknown. In the present study, we examined the effect of Snca ablation on brain PG level at basal conditions and following 30s of global ischemia. Brain PG were extracted with methanol, purified on C-18 cartridges, and analyzed by LC-MS/MS. We demonstrate,
for the first time, that Snca gene ablation Selleck GW4064 did not affect brain PG mass under normal physiological conditions. However, total PG mass and masses of individual PG were elevated similar to 2-fold upon global ischemia in the absence of Snca. These data are consistent with our previously observed reduction in 20:4n – 6 recycling through endoplasmic reticulum-localized acyl-CoA synthetase in the absence of Snca, which may result in the increased 20:4n – 6 availability for PG production in the absence of Snca during global Bumetanide ischemia and suggest a role for Snca in brain inflammatory response. (C) 2008 Elsevier Ireland Ltd. All rights reserved.”
“Human immunodeficiency virus type 1 Nef provides immune evasion by decreasing the expression of major histocompatibility
complex class I (MHC-I) at the surfaces of infected cells. The endosomal clathrin adaptor protein complex AP-1 is a key cellular cofactor for this activity, and it is recruited to the MHC-I cytoplasmic domain (CD) in the presence of Nef by an uncharacterized mechanism. To determine the molecular basis of this recruitment, we used an MHC-I CD-Nef fusion protein to represent the MHC-I CD/Nef complex during protein interaction assays. The MHC-I CD had no intrinsic ability to bind AP-1, but it conferred binding activity when fused to Nef. This activity was independent of the canonical leucine-based AP-binding motif in Net, it required residue Y320 in the MHC-I CD and residues E62-65 and P78 in Nef, and it involved the mu but not the gamma/sigma subunits of AP-1. The impaired binding of mutants encoding substitutions of E62-65 or P78 in Nef was rescued by replacing the Y320SQA sequence in the MHC-I CD with YSQL, suggesting that Nef allows the YSQA sequence to act as if it were a canonical mu-binding motif.