Up-regulating effect of hepatitis C virus core protein on laminin B1 chain gene promoter

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Identification and analysis of murine and rat homologous gene to human NS5ATP4 by bioinformatics method

AIM: To identify and analyze murine and rat NS5ATP4 cDNA sequences homologous to human NS5ATP4 cDNA sequence.

METHODS: The human NS5ATP4 cDNA was identified by combination of molecular biology and bioinformatics methods. The GenBank was searched for NS5ATP4 homologous cDNA sequences from mouse and rat. The identity and similarity were compared between human mouse and rat NS5ATP4 cDNA sequences.

RESULTS: The murine and rat NS5ATP4 cDNAs were consisted of 762 nucleotides (nt) and 756 nt, respectively. They encoded a protein of 253 amino acid residues (aa) and 251 aa, respectively. The similarity of murine and rat NS5ATP4 to human homologue was 90.29% and 84.25%, respectively, and the identity of murine and rat NS5ATP4 to human homologue was 95.65% and 86.96%, respectively.

CONCLUSION: The murine and rat NS5ATP4 cDNAs are identified.

Cloning and identification of NS5ATP2 gene and its spliced variant transactivated by hepatitis C virus non-structural protein 5A

AIM: To clone and identify a new gene NS5ATP2 and its spliced variant transactivated by hepatitis C virus non-structural protein 5A.

METHODS: On the base of subtractive cDNA library of genes transactivated by NS5A protein of hepatitis C virus, the coding sequence of new gene and its spliced variant were obtained by bioinformatics methods. Polymerase chain reaction (PCR) was conducted to amplify NS5ATP2 gene.

RESULTS: The coding sequence of new gene and its spliced variant were cloned and Identification successfully.

CONCLUSION: A novel gene has been recognized as the new target transactivated by HCV NS5A protein. These results bring some new clues for studying the biological functions of the new gene and pathogenesis of the viral proteins.

Effects of HCBP6 protein on transact-ivating function of HCV core protein

AIM: To study the inhibitory effects of HCBP6 on the transactivating effect of HCV core protein.

METHODS: The recombinant vectors expressive HCV core protein and HCBP6 protein were constructed, respectively, by routine molecular techniques. The hepatoblastoma cell line HepG2 were co-transfected. The chloramphenicol transferase (CAT) expressive levels under the SV40 early promoter were determined by an enzyme-linked immuno-sorbent assay (ELISA) kit.

RESULTS: The recombinant vectors of pcDNA3.1(-)-HCBP6 and pcDNA3.1(-)-core were constructed, and demonstrated correctly by restriction enzyme digestion and sequencing analysis. The hepatoblastoma cell line HepG2 was transfected with the vector alone or combined, respectively. The expression level of CAT indicated that the inhibitory rate was 40.4%-62.3%.

CONCLUSION: The expression of HCBP6 has inhibitory effects on the transacting activity of HCV core protein.

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Identification and characterization of retinol dehydrogenase 11 as a hepatitis C virus core protein-binding protein by yeast-two hybrid technique

AIM: To screen the hepatocyte protein interacting with HCV core protein.

METHODS: By using HCV core protein as a bait, yeast-two hybrid system 3 was employed for screening and identification of HCV core protein-binding proteins from a hepatocyte cDNA library expressed in yeast cells. The protein-protein interaction was confirmed by back-cross experiment, and the inserts of the expressive vectors were sequenced and analyzed by bioinformatics methods.

RESULTS: Among them we identified retinol dehydrogenase 11(RDH11/androgen- regulated short-chain dehydrogenase/reductase 1 (ARSDR1) as a HCV core protein-interacting protein. This is the first time, to the best of our knowledge, to know the fact that there are interactions of HCV core protein-retinol dehydrogenase 11.

CONCLUSION: The identification of retinol dehydrogenase 11 as the HCV core protein binding partner paves a new way for further understanding of the pathogenesis of HCV infection.

Identification and sequence analysis of mouse homologous gene coding for hepatitis C virus non-structural protein 5A-binding protein 37

AIM: To clone murine homologous gene to human NS5ABP37 gene, and to elucidate its biological functions and the possible effects in the pathogenesis of hepatitis C virus (HCV) infection.

METHODS: Yeast-two hybrid system was employed to screen the human liver cDNA library by using non-structural protein 5A (NS5A) of hepatitis C virus (HCV) as the bait. According to the homologous role between the species, a murine NS5ABP37 homologous to human NS5ABP37 was deduced by bioinformatics methods. The primary sequence of murine NS5ABP37 was searched for conserved domains by online tools of GeneBank.

RESULTS: Human NS5ABP37 was screened and cloned from human liver cDNA library by yeast-two hybrid system 3. The murine NS5ABP37 was deduced by bioinformatics methods. The open reading frame (ORF) of murine NS5ABP37 consisted of 1 488 nt encoding a protein of 495 amino acids. Calculated molecular weight was 54 583.67 dalton and predicted pI was 4.70. From the homologous protein search, murine NS5ABP37 was demonstrated homologous to leukocyte antigen related (LAR) protein precursor. The sequence of murine NS5ABP37 was deposited into GenBank, and the accession number was AY234860.

CONCLUSION: Successful identification and cloning of murine NS5ABP37, which is homologous to LAR protein precursor, paves a way for elucidating the biological function of murine NS5ABP37 and pathogenesis of hepatitis C virus infection.

Comparisons of differentially expressed genes transactivated by hepatitis B and C viral proteins using suppression subtractive hybridization and cDNA micro-array techniques

AIM: To clone and identify human genes transactivated by hepatitis B and C viral proteins via construction of a cDNA subtractive library with suppression subtractive hybridization (SSH) technique and cDNA microarray techniques.

METHODS: Suppression subtractive hybridization (SSH) and cDNA microarray techniques were used for screening and cloning of the target genes transactivated by hepatitis B and C viral proteins. The mRNA was isolated from HepG2 cells transfected recombinant vector expressing hepatitis B and C viral proteins and pcDNA3.1(-) empty vector,respectively. SSH and cDNA microarray were employed to analyze the differentially expressed DNA sequence between the two groups. In SSH assay, after restriction enzyme Rsa I digestion, small sizes of cDNAs were obtained. Then tester cDNA was divided into two groups and ligated to the specific adaptor 1 and adaptor 2, respectively. After tester cDNA was hybridized with driver cDNA twice and underwent two times of nested PCR and then was subcloned into T/A plasmid vectors to set up the subtractive library. Amplification of the library was carried out with E. coli strain JM109. The cDNA was sequenced and analyzed in GenBank with Blast search after PCR.

RESULTS: The subtractive library of genes transactivated by hepatitis B and C viral proteins was constructed successfully. The up-regulated and down-regulated genes from cDNA microarray assay was conducted for each of the hepatitis B and C viral proteins. The results were compared.

CONCLUSION: The obtained sequences may be target genes transactivated by hepatitis B and C viral proteins, among which some genes coding proteins involve cell cycle regulation, signal transduction, tumor immunity and development, and apoptosis.