RÉSUMÉ
In this study, the regulatory effect of the overexpression of polarity protein Lgl2 on the nuclear export ofinfluenza A virus nucleoprotein in infected cells was investigated. A stable Tet-Off inducible MDCK cell lineexpressing a fusion protein comprising Lgl2 and an enhanced yellow fluorescent protein were used. TCID50analysis and neuraminidase activity analysis revealed that replication of influenza A virus was inhibited in Lgl2overexpressing cells. By immunofluorescence microscopical observation at different time point post virusinfection, a retention of NP in cellular nucleus was found in Lgl2 overexpressing cells. Compared with normalMDCK cells, change in claudin-1 distribution between cell contacts caused by Lgl2 overexpression impairedthe barrier function of tight junction. These results suggest that changes in cell polarity induced by Lgl2overexpressing will affect virus NP transportation.
RÉSUMÉ
Abstract The aerobic degradation of aromatic compounds by bacteria is performed by dioxygenases. To show some characteristic patterns of the dioxygenase genotype and its degradation specificities, twenty-nine gram-negative bacterial cultures were obtained from sediment contaminated with phenolic compounds in Wuhan, China. The isolates were phylogenetically diverse and belonged to 10 genera. All 29 gram-negative bacteria were able to utilize phenol, m-dihydroxybenzene and 2-hydroxybenzoic acid as the sole carbon sources, and members of the three primary genera Pseudomonas, Acinetobacter and Alcaligenes were able to grow in the presence of multiple monoaromatic compounds. PCR and DNA sequence analysis were used to detect dioxygenase genes coding for catechol 1,2-dioxygenase, catechol 2,3-dioxygenase and protocatechuate 3,4-dioxygenase. The results showed that there are 4 genotypes; most strains are either PNP (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is positive) or PNN (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is negative). The strains with two dioxygenase genes can usually grow on many more aromatic compounds than strains with one dioxygenase gene. Degradation experiments using a mixed culture representing four bacterial genotypes resulted in the rapid degradation of phenol. Determinations of substrate utilization and phenol degradation revealed their affiliations through dioxygenase genotype data.