Transcription and replication of the influenza virus RNA genome occur in the nuclei of infected cells through the viral RNA-dependent RNA polymerase consisting of PB1, PB2, and PA. We previously identified a host factor designated RAF-1 (RNA polymerase activating factor 1) that stimulates viral RNA synthesis. RAF-1 is found to be identical to Hsp90. Here, we examined the intracellular localizat...

Lead (Pb2+) is a major environmental pollutant that has severe adverse effects on the nervous system. Similar human populations are at risk of suffering both Pb2+ toxicity and zinc (Zn) deficiency. Thus, in the present study we investigated whether Zn deficiency can increase the susceptibility of human neuroblastoma IMR-32 cells to Pb2+-induced oxidative stress which could trigger the activatio...

Artificially aminoacylated suppressor tRNAs were used to introduce photoreactive amino acids into model mitochondrial precursor proteins to probe the environment along the protein import pathway. Amino acids with benzophenone side chains of various lengths [DL-2-amino-3-(p-benzoylphenyl)propanoic acid (1) and DL-2-amino-5-(p-benzoylphenyl)pentanoic acid (2)] were incorporated at specific sites ...

Several amino acid changes have been previously implicated in adaptation of avian influenza viruses to human hosts, among them the D701N change in the PB2 polymerase subunit that also is the main determinant of avian virus pathogenesis in animal models. However, previous studies using recombinant viruses did not provide conclusive information of the contribution of this PB2 residue to pathogeni...

Influenza A virus (IAV) replicates in the upper respiratory tract of humans at 33 degrees C and in the intestinal tract of birds at close to 41 degrees C. The viral RNA polymerase complex comprises three subunits (PA, PB1 and PB2) and plays an important role in host adaptation. We therefore developed an in vitro system to examine the temperature sensitivity of IAV RNA polymerase complexes from ...

Host-adaptive strategies, such as the E627K substitution in the PB2 protein, are critical for replication of avian influenza A viruses in mammalian hosts. Here we show that mutation PB2-K526R is present in some human H7N9 influenza isolates, in nearly 80% of H5N1 human isolates from Indonesia and, in conjunction with E627K, in almost all seasonal H3N2 viruses since 1970. Polymerase complexes co...

In addition to influenza A subtypes, two distinct lineages of influenza B virus also cause seasonal epidemics to humans. Recently, Dudas et al. have done evolutionary analyses of reassortment patterns of the virus and suggested genetic lineage relationship between PB1, PB2, and HA genes. Using genetic plasmids and reassortant viruses, we here demonstrate that a homologous lineage PB1-PB2 pair e...

Hydrogels containing benzo-18-crown-6 were used to modify microcantilevers for measurements of the concentration of Pb2+ in aqueous solutions. These microcantilevers undergo bending deflection upon exposure to solutions containing various Pb2+ concentrations as the result of a swelling of the hydrogels. It was found that a concentration of 10(-6) M Pb2+ can be detected using this technology. Ot...

A comparative study of the removal of Pb2+ ions and Cr3+ ions was conducted to determine the efficiency of carbon nanotubes (CNTs) produced using microwave heating as an adsorbent in removing heavy metal ions from waste water. Optimization of parameters such as adsorbent dosage, pH value, agitation speed, and agitation time was done using the Design Expert software version 6.0. The statistical ...

Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also ...