Amyloid polymorphism underlies the prion strain phenomenon where a single protein polypeptide adopts different chain-folding patterns to form self-propagating cross-β structures. Three strains of the yeast prion [PSI], namely [VH], [VK], and [VL], have been previously characterized and are amyloid conformers of the yeast translation termination factor Sup35. Here we define specific sequences of the Sup35 protein that are necessary for in vivo propagation of each of these prion strains. By sequential substitution of residues 5–55 of Sup35 by proline and insertion of glycine at alternate sites in this segment, specific mutations have been identified that interfere selectively with the propagation of each of the three prion strains in yeast: the [VH] strain requires amino acid residues 7–21; [VK] requires residues 9–37; and [VL] requires residues 5 to at least 52. PNAS_September 9, 2008_vol.105 no.36 13345-13350 Read more...

The vaccinia virus WR53.5L/F14.5L gene encodes a small conserved protein that was not detected previously. However, additional proteomic analyses of different vaccinia virus isolates and strains revealed that the WR53.5 protein was incorporated into intracellular mature virus (IMV). The WR53.5 protein contains a putative N-terminal transmembrane region and a short C-terminal region... J. Virol. doi:10.1128/JVI.00816-08 Read more...

The Pax gene eyg is important for Drosophila eye development. eyg expression in the visual system changes dynamically during development. In this study, we found that the transcriptional regulation of eyg can be separated into four distinct temporal phases (E, L1, L2, and L3) and each is regulated by distinct cis regulatory elements. Utilizing these enhancers for temporal and spatially specific manipulations, we addressed the regulation and function of eyg at different developmental stages... Dev Biol. 2008 Jul 4. Read more...