• 제목/요약/키워드: Kozak sequence

검색결과 6건 처리시간 0.026초

Improved Homologous Expression of the Acidic Lipase from Aspergillus niger

  • Zhu, Si-Yuan;Xu, Yan;Yu, Xiao-Wei
    • Journal of Microbiology and Biotechnology
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    • 제30권2호
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    • pp.196-205
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    • 2020
  • In this study, the acidic lipase from Aspergillus niger (ANL) was homologously expressed in A. niger. The expression of ANL was significantly improved by the expression of the native ANL with the introns, the addition of the Kozak sequence and the optimization of the signal sequences. When the cDNA sequence of ANL fused with the glaA signal was expressed under the gpdA promoter in A. niger, no lipase activity could be detected. We then tried to improve the expression by using the full-length ANL gene containing three introns, and the lipase activity in the supernatant reached 75.80 U/ml, probably as a result of a more stable mRNA structure. The expression was further improved to 100.60 U/ml by introducing a Kozak sequence around the start codon due to a higher translation efficiency. Finally, the effects of three signal sequences including the cbhI signal, the ANL signal and the glaA signal on the lipase expression were evaluated. The transformant with the cbhI signal showed the highest lipase activity (314.67 U/ml), which was 1.90-fold and 3.13-fold higher than those with the ANL signal and the glaA signal, respectively. The acidic lipase was characterized and its highest activity was detected at pH 3.0 and a temperature of 45℃. These results provided promising strategies for the production of the acidic lipase from A. niger.

Saccharomyces cerevisae에서 한국산 겨우살이 유래 lectin A 및 B 유전자의 발현 (Expression of Recombinant Korean Mistletoe(KM) Lectin and B genes in Saccharomyces cerevisiae)

  • 최윤혁;김종배;양웅석;황철원
    • 생명과학회지
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    • 제14권5호
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    • pp.840-846
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    • 2004
  • 본 연구는 한국산 겨우살이 lectin유전자 (A 및 B chain) 을 효모 (Saccharmyces cerevisiae) 에 형질 전환시키는 시스템을 사용한 것으로, 효모내 효과적인 lectin유전자 발현을 위하여 유전자 상에 Kozak translation initiation sequence를 PCR을 이용 삽입, 변형시켜 재 클로닝 하였다. 변형된 lectin A 및 B 유전자를 포함하는 재조합 플라스미드는 S. cerevisiae INVSc (MATa, his3 $\Delta$l, leu2, trpl-289, ura3-52) 에 형질전환 되었다. 형질전환된 효모는 ABI 3700 system을 이용한 DNA 염기서열 분석을 통해 확인되었고 재조합 한국산겨우살이 lectin 발현을 위해 2% galactose를 사용하여 유도발현되었다. 재조합 lectin A 및 B 단백질은 SDS-PACE 및 western blotting 분석을 수행한 결과 약 29kDa 크기로 확인되었다. 재조합 lectin은 세포내 가용성 단백질 1mg중 1.24∼l.75 $\mu\textrm{g}$ 수준으로 발현되어짐을 ELISA 분석을 통해 확인하였다. 한편 lectin 유전자는 galartose 유도발현 후 36시간이 되 었을 때 발현량이 최대가 되었으며 lectin A 유전자의 경우 48 시간 이후에는 발현이 억제되었다.

Quadriplegia Following Epileptic Seizure : Things to Keep in Mind

  • Kozak, Hasan Huseyin;Yesilbudak, Zulal;Sisman, Lokman;Uca, Ali Ulvi
    • Journal of Korean Neurosurgical Society
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    • 제59권3호
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    • pp.319-321
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    • 2016
  • People with epilepsy are believed to be at a higher risk of incurring accidental injury than people who do not have seizures. The incidence of injury, either due to seizure or accident as a consequent of seizure is also high and varies from 0.03% to 3%. The most common injuries are head contusions, lacerations, burns and fractures. In this article, we present a case of quadriplegia after a generalized epileptic seizure.

TFF1 유전자의 C/T 다형성과 위암 민감성과의 연관성 (An Association of C/T Polymorphism in the TFF1 Gene and the Susceptibility to Gastric Cancer)

  • 맹은재;송재휘;성수윤;;박원상
    • Journal of Gastric Cancer
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    • 제8권3호
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    • pp.113-119
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    • 2008
  • 목적: TFF1 유전자의 -2bp에 위치하고 있는 단일염기다형성의 유전자형 및 대립형질 빈도와 H. pylori 감염 및 위암발생 민감성과의 연관성을 조사하고자 하였다. 대상 및 방법: 2000년 1월부터 2003년 12월까지 위 샘암종으로 근치적 수술을 시행 받은 167명과 정상 건강인 299명의 DNA를 이용하였다. TFF1 유전자의 단일염기다형성의 유전자형은 중합효소연쇄반응 후 제한효소를 이용한 제한 분절길이다형성과 single strand conformation polymorphism의 방법으로 분석하였다. 또한, H. pylori 감염은 Giemsa 염색으로 조사하였다. 결과: 정상 건강인의 TFF1 단일염기다형성에 대한 유전자형 및 대립형질의 빈도를 위암 환자군과 비교한 결과 통계적으로 의의가 없었다(P=0.715 & P=0.595). 위암 환자군을 성별로 나누어 정상 건강인과 비교한 경우에도 통계적 의의를 발견할 수 없었다. 또한, 위암 조직의 조직학적 소견 및 환자 연령과 TFF1 단일염기다형성의 유전자형 및 대립형질 빈도를 조사한 결과, 위암 조직의 조직학적 소견 및 연령은 TFF1 유전자 단일염기다형성과 무관하였다(P=0.088 & P=0.551). 한편, H. pylori 감염은 모두 39예에서 관찰되었는데 TFF1 유전자형과는 통계적으로 연관성이 없었다(P=0.7200). 결론: TFF1 유전자의 -2bp에 존재하는 단일염기다형성은 TFF1 단백의 합성에 큰 영향이 없으며 H. pylori 감염과 위암의 발생과는 무관하다는 것을 의미한다.

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Isolation and Characterization of the Colletotrichum acutatum ABC Transporter CaABC1

  • Kim, Suyoung;Park, Sook-Young;Kim, Hyejeong;Kim, Dongyoung;Lee, Seon-Woo;Kim, Heung Tae;Lee, Jong-Hwan;Choi, Woobong
    • The Plant Pathology Journal
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    • 제30권4호
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    • pp.375-383
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    • 2014
  • Fungi tolerate exposure to various abiotic stresses, including cytotoxic compounds and fungicides, via their ATP-driven efflux pumps belonging to ATP-binding cassette (ABC) transporters. To clarify the molecular basis of interaction between the fungus and various abiotic stresses including fungicides, we constructed a cDNA library from germinated conidia of Colletotrichum acutatum, a major anthracnose pathogen of pepper (Capsicum annum L.). Over 1,000 cDNA clones were sequenced, of which single clone exhibited significant nucleotide sequence homology to ABC transporter genes. We isolated three fosmid clones containing the C. acutatum ABC1 (CaABC1) gene in full-length from genomic DNA library screening. The CaABC1 gene consists of 4,059 bp transcript, predicting a 1,353-aa protein. The gene contains the typical ABC signature and Walker A and B motifs. The 5'-flanking region contains a CAAT motif, a TATA box, and a Kozak region. Phylogenetic and structural analysis suggested that the CaABC1 is a typical ABC transporter gene highly conserved in various fungal species, as well as in Chromista, Metazoans, and Viridiplantae. We also found that CaABC1 was up-regulated during conidiation and a minimal medium condition. Moreover, CaABC1 was induced in iprobenfos, kresoxim-methyl, thiophanate-methyl, and hygromycin B. These results demonstrate that CaABC1 is necessary for conidiation, abiotic stress, and various fungicide resistances. These results will provide the basis for further study on the function of ABC transporter genes in C. acutatum.

Construction of Mammalian Cell Expression Vector for pAcGFP-bFLIP(L) Fusion Protein and Its Expression in Follicular Granulosa Cells

  • Yang, Run Jun;Li, Wu Feng;Li, Jun Ya;Zhang, Lu Pei;Gao, Xue;Chen, Jin Bao;Xu, Shang Zhong
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권3호
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    • pp.401-409
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    • 2010
  • FLICE inhibitory protein (FLIP) is one of the important anti-apoptotic proteins in the Fas/FasL apoptotic path which has death effect domains, mimicking the pro-domain of procaspase-8. To reveal the intracellular signal transduction molecules involved in the process of follicular development in the bovine ovary, we cloned the c-FLIP(L) gene in bovine ovary tissue with the reverse transcription polymerase chain reaction (RT-PCR), deleted the termination codon in its cDNA, and directionally cloned the amplified c-FLIP(L) gene into eukaryotic expression vector pAcGFP-Nl, including AcGFP, and successfully constructed the fusion protein recombinant plasmid. After identifying by restrictive enzyme BglII/EcoRI and sequencing, pAcGFP-bFLIP(L) was then transfected into follicular granulosa cells, mediated by Lipofectamine 2000, the expression of AcGFP observed and the transcription and expression of c-FLIP(L) detected by RT-PCR and Western blot. The results showed that the cattle c-FLIP(L) was successfully cloned; the pAcGFPbFLIP(L) fusion protein recombinant plasmid was successfuly constructed by introducing a BglII/EcoRI cloning site at the two ends of the c-FLIP(L) open reading frame and inserting a Kozak sequence before the start codon. AcGFP expression was detected as early as 24 h after transfection. The percentage of AcGFP positive cells reached about 65% after 24 h. A 1,483 bp transcription was amplified by RT-PCR, and a 83 kD target protein was detected by Western blot. Construction of the pAcGFP-bFLIP(L) recombinant plasmid should be helpful for further understanding the mechanism of regulation of c-FLIP(L) on bovine oocyte formation and development.