Résumé
In 2005, an avian influenza virus stain was isolated from Parrot in Guangdong, which was then genotyped as H5N2 subtype and designated as A/Parrot/Guangdong/268/2005. According to the current OIE definition on the low-pathogenicity of avian influenza virus, the strain was recognized as a low pathogenic avian influenza virus due to the presence of one basic amino acid residue at the HA cleavage site. Some molecular characteristics of the virus, such as potential glycosylation sites in HA and NA, receptor binding sites of HA, and drug resistance site of NA, showed no variations. To analyze molecular evolution of this strain, we selected the sequences of H5N2 subtype AIVs from GenBank and established the phylogenetic trees. Our results indicated that this strain shared the highest homologies with the H5N2 LPAI isolate A/Pheasant/NJ/1355/1998-like. Phylogenic analysis revealed the isolate, together with A/Chicken/Pennsylvania/1/1983 (H5N2), belonged to America lineages and clustered with A/Pheasant/NJ/1355/1998-like.
Sujets)
Animaux , Séquence d'acides aminés , Évolution moléculaire , Gènes viraux , Génétique , Sous-type H5N2 du virus de la grippe A , Génétique , Grippe chez les oiseaux , Virologie , Perroquets , Virologie , Phylogenèse , Analyse de séquence d'ADN , Protéines virales , Chimie , GénétiqueRésumé
To produce recombinant Buthus martensii Karsch insect toxin (BmK IT), BmK IT cDNA which fused a hexahistidine sequence at the C-terminus by PCR was inserted into pTWIN1 expression vector fused in frame with an upstream Ssp DnaB intein gene. The expression plasmid was transformed into E. coli BL21 (DE3) strain and protein expression was induced by IPTG. The CBD-Intein-BmK IT(his6) fusion protein was purified from cell lysates using Ni-NTA resin affinity chromatography. The intein was removed from fusion protein by on-column intein-mediated cleavage. BmK IT(his6) was purified through Superdex 75 gel chromatography to more than 95% homogeneity. The purified protein has both correct secondary structure and insecticidal activity.
Sujets)
Animaux , Chromatographie d'affinité , Chromatographie sur gel , Escherichia coli , Génétique , Métabolisme , Histidine , Génétique , Intéines , Génétique , Oligopeptides , Génétique , Protéines de fusion recombinantes , Génétique , Venins de scorpion , Génétique , Transformation génétiqueRésumé
<p><b>OBJECTIVE</b>To investigate the expression and function of PKD1 and PKD2 in different kidney tissues and cell lines.</p><p><b>METHODS</b>Immunoprecipitation, Western blotting, In situ hybridization and immunohistochemical staining methods were used to observe the expression of PKD1 mRNA and PKD2 mRNA and their protein abundance in different kidney tissues and cell lines.</p><p><b>RESULTS</b>Coordinate expressions of PKD1 and PKD2 were found in all kidney tissues and cell lines. Distribution of PKD1 mRNA and PKD2 mRNA and their protein polycystin-1 and polycystin-2 in normal human adult kidney tissue were mainly expressed in the medullary collecting ducts and distal tubules. Positive staining was also found in the majority of cyst-lining epithelial cells of PKD1 cystic kidney tissue, PKD1 cyst-lining epithelia cell line and LLC-PK1. The expression level of them in cystic epithelia of ADPKD kidney tissue was much higher than that in adult renal tubules (P < 0.01).</p><p><b>CONCLUSIONS</b>Similar expression pattern of PKD1 and PKD2 and their different tissue distribution in different kidney tissues show that the molecular mutuality of PC-1 and PC-2 might be the base of their functional correlation. Polycystins might play an important role in the maintenance of tubular architecture.</p>