RESUMEN
In Helicobacter pylori (H. pylori)-induced gastric ulceration, NF-kappaB regulates the expression of inflammatory genes. NF-kappaB is activated by phosphorylation of its endogenous inhibitor, IkappaBalpha. The possible involvement of mitogen-activated protein kinase (MAPK) on NF-kappaB activation has been suggested in various cells. Present study aims to investigate whether H. pylori in a Korean isolate induces phosphorylation of IkappaBalpha and whether H. pylori-induced phosphorylation of IkappaBalpha is mediated by MAPK in gastric epithelial AGS cells. AGS cells were treated with MAPK inhibitors (U0126 for extracellular signal-regulated kinase, SB203580 for p38 kinase, SP600125 for c-Jun NH2-terminal protein kinases) and stimulated with H. pylori. As a result, H. pylori increased phospho-specific IkappaBalpha accompanied with the decrease in control IkappaBalpha. H. pylori-induced phosphorylation of IkappaBalpha was inhibited by treatment of U0126, but not by SB203580 or SP600125. In conclusion, extracellular signal-regulated kinase induces phosphorylation of IkappaBalpha in H. pylori-infected AGS cells.
Asunto(s)
ADN Bacteriano , Infecciones por Helicobacter/patología , Helicobacter pylori/patogenicidad , Quinasa I-kappa B/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Proteínas Bacterianas/metabolismo , Línea Celular Tumoral , Células Epiteliales/enzimología , Mucosa Gástrica/enzimología , Humanos , FosforilaciónRESUMEN
We have used an antibody against the functional homolog of the cdc2 kinase of maize to localize the p34cdc2 protein within dividing cells of the root apex and the stomatal complex of leaf epidermis. The microtubule cytoskeletal structure of plant cells was visualized concomitantly with a monoclonal antibody specific for [alpha]-tubulin. We found that the cdc2 protein is localized mainly to the nucleus in plant cells at interphase and early prophase. This finding contrasts markedly with the predominantly cytoplasmic staining obtained using antibody to the PSTAIRE motif, which is common to cdc2 and numerous cdc2-like proteins. In a subpopulation of root cells at early prophase, the p34cdc2 protein is also distributed in a band bisecting the nucleus. Double labeling with the maize p34cdc2Zm antibody and tubulin antibody revealed that this band colocalizes with the preprophase band (PPB) of microtubules, which predicts the future division site. Root cells in which microtubules had been disrupted with oryzalin did not contain this band of p34cdc2 protein, suggesting that formation of the microtubule PPB is necessary for localization of the p34cdc2 kinase to the plane of the PPB. The p34cdc2 protein is also localized to the nucleus and PPB in cells that give rise to the stomatal complex, including those cells preparing for the highly asymmetrical divisions that produce subsidiary cells. Association of the p34cdc2 protein with the PPB suggests that the cdc2 kinase has a role in establishing the division site of plant cells and, therefore, a role in plant morphogenesis.
RESUMEN
Chickens were immunized with the lipid emulsion system and Salmonella typhimurium mitogen adjuvant for fowl plus synthetic peptides corresponding to the divergent amino acid sequences at the carboxyl terminus of each of two different alpha-tubulin isoforms from Arabidopsis thaliana. Antibodies were extracted from egg yolks and used in immunoblot assays to determine the time course of antibody production in two chickens. Specific immunoglobulin production increased 10-14 days after the primary injection in both chickens and reached peak levels shortly thereafter. Booster injections helped maintain IgG production, which eventually dropped off after the final injection.