PubMed Health⌕ Search

Biomedical subjects

G G Prikhod'ko

Publications and source records attributed to G G Prikhod'ko.

13 recordsLinked to original sources
PubMed2001

Infection with Langat Flavivirus or expression of the envelope protein induces apoptotic cell death.

Langat (LGT) flavivirus, derived from infectious full-length cDNA clone 636, was investigated for its apoptotic activities in mouse neuroblastoma (Neuro-2a) and simian kidney (Vero and LLC-MK(2)) cells. The hallmark of apoptosis, cleavage of cellular DNA, was observed 48 h after infection of Vero, LLC-MK(2), and Neuro-2a cells by electrophoresis analysis. Apoptosis in infected cells was also confirmed by TUNEL assay. LGT-infected Neuro-2a cells showed an increase in caspase-3-like protease (DEVDase) activity. Expression of the major envelope glycoprotein (E) alone reduced cell viability in both Vero and Neuro-2a cells, and the baculovirus P35 protein, which inhibits multiple caspases, completely blocked this effect. Cleavage of cellular DNA was observed in E gene-transfected Vero cells by TUNEL assay. Expression of E protein or caspase-9 resulted in activation of caspase-3-like proteases in Neuro-2a cells. The caspase-3-like protease specific inhibitor, Ac-DEVD-CHO peptide, partially inhibited E protein- or caspase-9-induced apoptosis in Neuro-2a cells. These observations indicate that infection of cells with LGT virus or expression of LGT virus E protein induces apoptosis through a caspase-3-like protease pathway.

Animals↗
PubMed1999

Baculovirus p33 binds human p53 and enhances p53-mediated apoptosis.

In vertebrates, p53 participates in numerous biological processes including cell cycle regulation, apoptosis, differentiation, and oncogenic transformation. When insect SF-21 cells were infected with a recombinant of the baculovirus Autographa californica nuclear polyhedrosis virus (AcMNPV) overexpressing human p53, p53 formed a stable complex with the product of the AcMNPV orf92, a novel protein p33. The interaction between p53 and p33 was further confirmed by immunoprecipitation studies. When individually expressed in SF-21 cells, human p53 localized mainly in the nucleus whereas baculovirus p33 displayed diffuse cytoplasmic staining and punctuate nuclear staining. However, coexpression of p33 with p53 resulted in exclusive nuclear localization of p33. In both SF-21 and TN-368 cells, p53 expression induced typical features of apoptosis including nuclear condensation and fragmentation, oligonucleosomal ladder formation, cell surface blebbing, and apoptotic body formation. Coexpression of p53 with a baculovirus inhibitor of apoptosis, p35, OpIAP, or CpIAP, blocked apoptosis, whereas coexpression with p33 enhanced p53-mediated apoptosis approximately twofold. Expression of p53 in SF-21 cells stably expressing OpIAP inhibited cell growth in the presence or absence of p33. Thus, human p53 can influence both insect cell growth and death and baculovirus p33 can modulate the death-inducing effects of p53.

Amino Acid Sequence↗
PubMed1997

Gypsy retrotransposon as a tool for the in vivo analysis of the regulatory region of the optomotor-blind gene in Drosophila.

We report here a method for the in vivo dissection of the regulatory region of a gene in the Drosophila genome. Our system includes (i) the reporter genes lacZ and white to detect transcriptional enhancer and silencer activities in a target gene, (ii) an efficient way to induce integration of gypsy elements in the genome, and (iii) unidirectional blocking of regulatory activities by the gypsy element, which is dependent on the su(Hw) protein. The optomotor-blind (omb) gene was analyzed. In the omb(P1) line, a P[lacW] construct is inserted about 1.4 kb upstream of the omb transcription start site. The lacZ reporter gene within P[lacW] exhibits the same expression pattern as omb. The white reporter gene is expressed in a "bipolar" pattern. We induced high frequency gypsy mobilization in omb(P1) and identified two lines (D11 and D13-1) with altered eye pigmentation pattern, which is dependent on su(Hw) activity. A gypsy element was found inserted in the first intron of omb in D13-1 and in P[lacW] in D11. These results indicate that it is the blocking of regulatory activities by gypsy that caused the changes in the white reporter gene expression. The effect of these gypsy insertions on the expression patterns allowed us to predict several aspects of the organization of the regulatory elements in the omb locus.

Animals↗
PubMed1995

Biochemical characterization of VspI methyltransferase.

The gene (vspIM) encoding VspI methyltransferase (MTase) has previously been cloned and sequenced, and shown to belong to the gamma class of m6-adenine MTases [Degtyarev et al., Nucleic Acids Res. 21 (1993) 2015]. Here it is shown that the MTase modifies the third adenine within the recognition sequence 5'-ATTAAT-3'.

Base Sequence↗
PubMed1993

Identification of DNA binding proteins in vaccinia virus by DNA-protein crosslinking.

DNA binding proteins of vaccinia virus (VV) virions, strain LIVP, have been studied by their covalent crosslinking to DNA, using two-dimensional gel retardation electrophoresis of crosslinked DNA and proteins as well as the 'protein image' hybridization assay. Five proteins with molecular masses of 16, 25, 27, 41 and 54 kDa, respectively, associated with all analysed DNA sequences, including early and late genes and their promoters, have been identified.

Cross-Linking Reagents↗
PubMed1991

[5-Variable genome sequence of the LIVP vaccinia virus. A possible role for short direct repeats in the formation of deletions].

HindIII-O/N DNA fragments of vaccinia virus (VV) of the LIVP strain were mapped using thirteen restriction endonucleases. Nucleotide sequences of the HindIII-O fragment (1530 bp) as well as of a site of the HindIII-N genome fragment 353 bp in size were determined. Comparison of restriction maps and nucleotide sequences of VV strains (WR and LIVP) demonstrated that DNA of VV LIVP contained % deletions and 2 insertions. "Reliable" short direct repeats were localized and their possible role in formation of DNA deletions was shown. It was suggested that VV endonuclease and DNA-ligase participate in replication and repair processes. Mechanism of formation of variable sequences of viral genomes is discussed.

Amino Acid Sequence↗
PubMed1991

[Cloning, sequencing and translation analysis of the Vaccinia virus LIVP HINDIII N genome fragment].

The sequence of vaccinia virus (VV) LIVP HindIII N DNA fragment has been determined to be 2215 b.p. Three open reading frames designated LN1, N1 and NO1 and coding polypeptides with the calculated molecular masses (32.5 kDa, 21.8 kDa and 47.8 kDa) were located. mRNAs selected by hybridization with the VV HindIII N were translated in rabbit reticulocyte lysate. Proteins of genes for host range and resistance to alpha-amanitin corresponding to 29 and 47 kDa were detected. Two forms of polypeptides of the ORF LN1 (32 and 29K), and anomalous electrophoresis mobility of the ORF LN1 are discussed.

Amino Acid Sequence↗
PubMedDate not supplied

[Determination of the substrate specificity of Bpu101 restrictase with an unusual recognition segment].

A new enzyme Bpu10I was isolated from Bacillus pumilus. This enzyme is not an isoschizomer of any known restriction endonucleases. The search of possible recognition sequences was carried out in sequences ABCNiDEF (i = 0.6) on substrate DNA lambda CI857, T7, pBR322. The recognition sequence and cleavage sites of restriction endonuclease Bpu10I have been determined as CCTNAGC. GGANTCG

Bacillus↗