• Title/Summary/Keyword: Overlapping open reading frame

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Finding and Characterization of Viral Nonstructural Small Protein in Prospect Hill Virus Infected Cell

  • Nam, Ki-Yean;Chung, Dong-Hoon;Choi, Je-Won;Lee, Yun-Seong;Lee, Pyung-Woo
    • The Journal of Korean Society of Virology
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    • v.29 no.4
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    • pp.221-233
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    • 1999
  • Prospect Hill Virus (PHV) is the well known serotype of hantavirus, a newly established genus in family Bunyaviridae. Extensive studies have upheld the original view of PHV genetics with three genes such as nucleocapsid (N) protein, envelope proteins (G1, G2) and RNA dependent RNA polymerase. In this study, we report the existence of additional gene that is encoded in an overlapping reading frame of the N protein gene within S genome segment of PHV. This gene is expected to encode a nonstructural small (NSs) protein and it seems to be only found in PHV infected cell. The presence and synthesis of NSs protein could be demonstrated in the cell infected with PHV using anti-peptide sera specific to the predicted amino acid sequence deduced from the second open reading frame. Ribosomal synthesis of this protein appears to occur at AUG codon at the 83rd base of S genome segment, downstream of N protein initiation codon. This protein is small in size (10.4 KDa) and highly basic in nature. The expression strategy of NSs protein appears that a signal mRNA is used to translate both N and NSs protein in PHV infected cell. 10 KDa protein in virus infected cell lysates can bind to mimic dsRNA. This fact strongly suggests that NSs protein may be involved in virus replication on late phase of viral life cycle.

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Isolation and Characterization of cDNA Encoding Pyridoxal Kinase from Ovine Liver

  • Lee, Hyun-Shik;Choi, Soo-Young;Kwon, Oh-Shin
    • BMB Reports
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    • v.32 no.5
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    • pp.502-505
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    • 1999
  • cDNA fragments of ovine liver pyridoxal kinase were amplified by PCR using degenerate oligonucleotide primers derived from partial amino acids sequences of the enzyme. Using PCR products as probes, several overlapping cDNA clones were isolated independently from an ovine liver and a human brain cDNA library. The largest cDNA clone for each was selected for sequence analysis. The ovine liver cDNA encodes a polypeptide of 297 amino acid residues with Mr of 32,925, whereas the human clone is comprised of an open reading frame encoding 312 amino acid residues with Mr of 35,102. The deduced sequence of the human brain enzyme is completely identical to that of human testes cDNA recently reported (Hanna et al., 1997). The ovine enzymes have approximately 77% sequence identity with the human enzyme although the two sequences are completely different in the N-terminus comprising 32 residues. This result suggests that pyridoxal kinase is highly homologous in mammalian species.

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Molecular Cloning of Mutant cDNA of PU.1 Gene (PU.1 유전자(cDNA)의 인위적 변이체 클로닝)

  • 류종석;유시현
    • KSBB Journal
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    • v.10 no.5
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    • pp.499-509
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    • 1995
  • PU.1, a tissue-specific transcription activator, binds to a purine-rich sequence(5'-GAGGAA-3') called PU box. The PU.1 cDNA consists of an open reading frame of 816 nucleotides coding for 272 amino acids. The amino terminal end is highly acidic, while the carboxyl terminal end is highly basic. Transcriptional activation domain is located at the amino terminal end, while DNA binding domain is located at the carboxyl terminal end. Activation of PU.1 transcription factor is supposed to be accomplished by the phosphorylation of serine residue(s). There exist 22 serines in the PU.1. Five(the 41, 45, 132$.$133, and 148th) of the serines(plausible phosphorylation site by casein kinase II), are the primary targets of interest in elucidating the molecular mechanism(s) of the action of the PU.1 gene. In this study, PU.1 cDNA coding for the five serine residues(41th AGC, 45th AGC, 132$.$133th AGC$.$TCA, and 148th TCT), was mutated to alanine codon(41th GCC, 45th GCC, 132$.$133th GCC$.$GCA, and 1481h GCT), respectively, by Splicing-Overlapping-Extension(SOE) using Polymerase Chain Reaction(PCR). And each mutated cDNA fragments was ligated into pBluescript KS+ digested with HindIII and Xba I, to generate mutant clones named pKKS41A, pRKS45A, pMKS132$.$133A, and pMKS148A. The clones will be informative to study the "Structure and Function" of the immu-nologically important gene, PU.1.

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Molecular Characterization of a Korean Isolate of Human Norovirus, the Hu/NLV/Gunpo/2006/KO Strain (인체 노로바이러스의 한국분리주 Hu/NLV/Gunpo/2006/KO의 분자생물학적 특성)

  • Jeong, Ah-Yong;Yun, Sang-Im;Jee, Young-Mee;Kang, Yoon-Sung;Lee, Young-Min
    • Korean Journal of Microbiology
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    • v.45 no.2
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    • pp.105-111
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    • 2009
  • Norovirus (NV) with a variety of genotypes, a member of the family Caliciviridae, causes acute nonbacterial gastroenteritis in humans. We determined the nucleotide sequence of three open reading frames (ORFs) of a NV Korean strain and characterized the genetic relationship with others. The Korean strain designated Hu/NLV/Gunpo/2006/KO was isolated from the stool specimen of a 2-year-old female suffering from gastroenteritis. By performing reverse transcription and PCR amplification, three overlapping cDNAs were synthesized and used for direct sequencing. We found that like other NVs, this strain contains three ORFs: ORF1, 5,100 bp; ORF2, 1,647 bp; ORF3, 765 bp. Of 35 NVs, ORF1 had a level of genetic diversity lower than ORF2 and ORF3, of which the C-termini of the ORF2 and ORF3 showed a relatively high degree of genetic diversity. Phylogenetic analyses indicated that the Korean strain belonged to genogroup II, with Saitama U1, Gifu'96, Mc37, and Vietnam 026 being formed a single genetic cluster. The nucleotide sequence information of three ORFs of a NV Korean isolate will be useful not only for the development of a diagnostic tool and understanding of genetic relationship, but also provide important basic information for the functional analysis of their gene products.

Analysis of a Heterocyst-controlling Gene and Its Expression upon Nitrogen Starvation in a Cyanobacterium (남조류의 이형세포 조절 유전자와 질소량에 따른 유전자 발현의 분석)

  • Bae, Jeong-Jin;Yoon, Ho-Sung
    • Korean Journal of Ecology and Environment
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    • v.38 no.4 s.114
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    • pp.510-517
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    • 2005
  • The filamentous cyanobacterium Anabaena is capable of both photosynthesis and nitrogen fixation which probably facilitated its incredible adaptation and proliferation in freshwater environments. A small gene, patS, was found to block nitrogen fixing cells from developing which resulted in death of Anabaena in the absence of combined nitrogen sources. We analyzed the DNA sequences in the vicinity of the patS gene by using a codon usage program and detected no codon bias other than the patS open reading frame. Three overlapping cosmids that contain the patS gene were identified, and the presence of other known heterocyst-controlling genes was examined. The patS expression in response to nitrogen starvation was analyzed at the level of transcription and translation by using Northern blot analyses and lacZ-reporter-gene fusion experiments, respectively. The patS expression increased rapidly (within 12 hours) upon the removal of combined nitrogen from the media.

Characterization of Mud Loach (Misgurnus mizolepis) Apolipoprotein A-I: cDNA Cloning, Molecular Phylogeny and Expression Analysis (미꾸라지(Misgurnus mizolepis) Apolipoprotein A-I cDNA의 구조, 분자계통 및 발현 특징 분석)

  • Lee, Youn-Ho;Noh, Jae-Koo;Kim, Keun-Yong;Cho, Young-Sun;Nam, Yoon-Kwon;Kim, Dong-Soo
    • Journal of Aquaculture
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    • v.20 no.1
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    • pp.65-72
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    • 2007
  • Full length complementary DNA encoding apolipoprotein A-I (apoA-I) was isolated and characterized in mud loach (Misgurnus mizolepis). Mud loach apoA-I cDNA encoding 24 bp of 5'-untranslated region (UTR), 762 bp of single open reading frame (ORF) consists of 254 amino acids and 293 bp of 3'-UTR excluding stop codon and poly (A+) tail. Two overlapping polyadenylation signals (AATAAAATAAA) was found 9 bp prior to the poly (A+) tail. Mud loach apoA-I represented considerable homology to those from other teleost species at amino acid level with conserving common features of vertebrate apoA-I. Molecular phylogenetic analysis inferred the phylogenetic hypothesis that was generally in accordance with the previous taxonomic relationship. Apolipoprotein A-I mRNA was detected in various tissues, but the mRNA levels were quite varied depending on tissues based on semi-quantitative RT-PCR. Liver and brain showed the significantly higher levels of apoA-I transcripts than other tissues. mRNA expression of apoA-I was quite low in very early stage of embryonic development, however dramatically enhanced from 8 hours post fertilization. This increased mRNA level was retained consistently up to 14 days post hatching.