The hepatitis E virus (HEV) is the causative agent of hepatitis E, an acute form of viral hepatitis. The biology and pathogenesis of HEV remain poorly understood. We have used in vitro binding assays to show that the HEV ORF3 protein (pORF3) binds to a number of cellular signal transduction pathway proteins. This includes the protein tyrosine kinases Src, Hck, and Fyn, the p85␣ regulatory subunit of phosphatidylinositol 3-kinase, phospholipase C␥, and the adaptor protein Grb2. A yeast two-hybrid assay was used to further confirm the pORF3-Grb2 interaction. The binding involves a proline-rich region in pORF3 and the src homology 3 (SH3) domains in the cellular proteins. Competition assays and computer-assisted modeling was used to evaluate the binding surfaces and interaction energies of the pORF3⅐SH3 complex. In pORF3-expressing cells, pp60 src was found to associate with an 80-kDa protein, but no activation of the Src kinase was observed in these cells. However, there was increased activity and nuclear localization of ERK in the pORF3-expressing cells. These studies suggest that pORF3 is a viral regulatory protein involved in the modulation of cell signaling. The ORF3 protein of HEV appears to be the first example of a SH3 domain-binding protein encoded by a virus that causes an acute and primarily self-limited infection.Hepatitis E virus (HEV), 1 the causative agent for hepatitis E, is a waterborne pathogen endemic to much of the developing world where it causes rampant sporadic infections and large scale epidemics (1-4). While the infection is self-limited with no associated chronicity, a fraction of the patients progress to fulminant hepatitis (5, 6), the most severe form of acute hepatitis. High mortality rates of 20 -30% reported for HEV infection during pregnancy (7,8) are also the result of fulminant hepatitis. The reasons for this and the mechanisms of viral pathogenesis are not known. The studies on HEV biology and pathogenesis have been severely restricted by the lack of a reliable cell culture system and small animal models of viral infection. We have used subgenomic expression strategies to study the properties and functions of individual HEV gene products toward understanding viral replication and pathogenicity (9 -12).The HEV genome is a ϳ7.5-kilobase polyadenylated, positive-sense RNA that contains three open reading frames (ORFs) designated ORF1, ORF2, and ORF3 (13). The ORF3 of HEV encodes a protein of ϳ13.5 kDa, called pORF3, for which no function has been assigned. When expressed in animal cells, pORF3 is phosphorylated at a single serine residue (Ser 80 ) in its 123-amino acid primary sequence (11). In vitro phosphorylation experiments suggested that pORF3 may be a substrate for the mitogen-activated protein (MAP) kinase, and subcellular fractionation revealed its association with the cytoskeleton (11). Recent results using inhibitors, activators, and dominant negative alleles show that pORF3 is a substrate for the extracellular signal-regulated kinase (ERK) as well as the stressactivated pr...

Protein extraction from plants like the halophyte Salicornia europaea has been problematic using standard protocols due to high concentrations of salt ions in their cells. We have developed an improved method for protein extraction from S. europaea, which allowed us to remove interfering compounds and salt ions by including the chemicals borax, polyvinylpolypyrrolidone, and phenol. The comparative study of this method with several other protocols using NaCl-treated S. europaea shoots demonstrated that this method gave the best distinction of proteins on 2-DE gels. This protocol had a wide range of applications as high yields and good distinction of 1-DE gels for proteins isolated from twelve other plants were rendered. In addition, we reported results of 2-DE using the recalcitrant tissue of the S. europaea roots. We also demonstrated that this protocol is compatible with proteomic analysis as eight specific proteins generated by this method have been identified by MS. In conclusion, our newly developed protein extraction protocol is expected to have excellent applications in proteomic studies of halophytes.

Bangladesh is a densely populated developing country. Both industrialization and geological sources have caused widespread heavy metal and metalloid pollution in Bangladesh, which is now posing substantial threats to the local people. In this review, we carried out one of the most exhaustive literature analyses on the current status of Bangladesh heavy metal and metalloid pollution, covering water, soil, and foods. Analysis showed that soils near high traffic and industrial areas contain high concentrations of heavy metals and metalloids. Agricultural land and vegetables in sewage-irrigated areas were also found to be heavy metal- and metalloid-contaminated. River water, sediment, and fish from the Buriganga, Turag, Shitalakhya, and Karnaphuli rivers are highly contaminated with cadmium (Cd), lead (Pb), and chromium (Cr). Particularly, groundwater arsenic (As) pollution associated with high geological background levels in Bangladesh is well reported and is hitherto the largest mass poisoning in the world. Overall, the contamination levels of heavy metals and metalloids vary among the cities, with industrial areas being most polluted. In all, this review provides a quantitative identification of the As, Pb, Cd, and Cr contamination hotspots in Bangladesh based on the literature, which may be useful to environmental restorationists and local policy makers.