Expanding the proteome of an RNA virus by phosphorylation of an intrinsically disordered viral protein

The human proteome contains myriad intrinsically disordered proteins. Within intrinsically disordered proteins, polyproline-II motifs are often located near sites of phosphorylation. Wehave used an unconventional experimental paradigm to discover that phosphorylation by protein kinase A (PKA) occurs in the intrinsically disordered domain of hepatitis C virus nonstructural protein 5A (NS5A) on Thr-2332 near one of its polyproline-II motifs. Phosphorylation shifts the conformational ensemble of the NS5A intrinsically disordered domain to a state that permits detection of the polyproline motif by using 15N-, 13C-based multidimensional NMR spectroscopy. PKA-dependent proline resonances were lost in the presence of the Src homology 3 domain of c-Src, consistent with formation of a complex. Changing Thr-2332 to alanine in hepatitisCvirus genotype 1b reduced the steady-state level of RNA by 10-fold; this change was lethal for genotype 2a. The lethal phenotype could be rescued by changing Thr-2332 to glutamic acid, a phosphomimetic substitution. Immunofluorescence and transmission electron microscopy showed that the inability to produce Thr(P)-2332-NS5A caused loss of integrity of the virus-induced membranous web/replication organelle. An even more extreme phenotype was observed in the presence of small molecule inhibitors of PKA. We conclude that the PKA-phosphorylated form of NS5A exhibits unique structure and function relative to the unphosphorylated protein. We suggest that post-translational modification of viral proteins containing intrinsic disorder may be a general mechanism to expand the viral proteome without a corresponding expansion of the genome

Comparative morphometric studies of the sting apparatus of the worker bees of four different Apis species (Apis dorsata, Apis mellifera, Apis cerana and Apis florea)

Two glands associated with the sting apparatus of worker honey bees produce venom. The aim of this study was to analyse the size and morphometrics of the sting apparatus of worker bees of four Apis species. The sting apparatus consists of a venom gland, venom sac or venom reservoir and sting. These structures are located in the posterior region of the abdomen between the rectum and ovaries. The venom gland is a long tubular filamentous region (acid gland) connected to a reservoir at its proximal region in which the venom is stored. The distal end of the reservoir or venom sac is connected to the bulb of the sting, which leads into the venom canal present inside the shaft of the sting. Little variation was observed in the morphology of the sting apparatus of the different Apis species, although significant variations were found in the length and width of the different parts of sting apparatus. Copyright © 2013 IBRA

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Not AvailableSingle Nucleotide Polymorphisms in Alpha-Lactalbumin gene in Murrah and South Kanara Buffaloes (Bubalus bubalis).Not Availabl