• 제목/요약/키워드: $\beta$-strand

검색결과 48건 처리시간 0.016초

Protein unfolding by ATP-dependent proteases

  • Lee, Cheolju;Michael Schwartz;Sumit Prakash;Masahiro Iwakura;Andreas Matouschek
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.34-34
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    • 2003
  • Protein unfolding is a key step in several cellular processes, including protein translocation across some membranes and protein degradation by ATP-dependent proteases. C1pAP protease and the proteasome can actively unfold proteins in a process that hydrolyzes ATP, These proteases catalyze unfolding by processively unraveling their substrates from the attachment point of the degradation signal. As a consequence, the ability of a protein to be degraded depends on its structure as well as its stability. An ${\alpha}$-helix is easier to unravel than a ${\beta}$-strand. In multidomain proteins, independently stable domains are unfolded sequentially. The steric constraints imposed on substrate proteins during their degradation by the proteasome were investigated by constructing a model protein in which specific parts of the polypeptide chain were covalently connected through disulfide bridges. The cross-linked model proteins were fully degraded by the proteasome, but two or more cross-links retarded the degradation slightly. Our results suggest that the pore of the proteasome allows the concurrent passage of at least three stretches of a polypeptide chain, and also explain the limited degradation by the proteasome that occurs in the processing of the transcription factor NF-KB, and also implicate difficulty in degradation of amyloidal aggregates by the proteasome

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Analysis of Structure and Expression of Grapevine 2-oxoglutarate Oxygenase Genes in Response to Low Temperature

  • Kim, Seon Ae;Ahn, Soon Young;Yun, Hae Keun
    • 원예과학기술지
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    • 제34권1호
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    • pp.46-54
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    • 2016
  • 2-Oxoglutarate (2OG) acts as a signaling molecule and plays a critical role in secondary metabolism in a variety of organisms, including plants. Six 2-oxoglutarate (2OG) and Fe(II) oxygenase (2OGO) genes, VlCE2OGO1 [Vitis labruscana 2-oxoglutarate (2OG) and Fe(II) oxygenase 1], VlCE2OGO2, VlCE2OGO3, VlCE2OGO4, VlCE2OGO5, and VlCE2OGO6, which show different expression patterns upon transcriptome analysis of 'Campbell Early' grapevine exposed to low temperature for 4 weeks, were analyzed for their structure and expression. Comparison of the deduced amino acid sequences of the 2OGO genes from the V. labruscana transcripts revealed sequence similarities of 38.6% (VlCE2OGO1 and VlCE2OGO2) to 19.2% (VlCE2OGO2 and VlCE2OGO3). The lengths of these genes ranged from 1053 to 2298 bp, and they encoded 316 to 380 amino acids. The prediction of the secondary structure of the encoded proteins by Self-Optimized Prediction Method with Alignment (SOPMA) indicated that all the genes contained alpha helix (23.95 to 41.71%), extended strand (16 to 22.34%), beta turn (6.65 to 9.22%), and random coil (32.97 to 51.58%) in the analysis. Specific primers from unique regions in each gene obtained by alignment of nucleotide sequences were used in real time PCR for analysis of gene expression. All tested genes showed differential expression in grapevines exposed to low temperature. Of the six transcripts, VlCE2OGO1, VlCE2OGO2, and VlCE2OGO3 were up-regulated and VlCE2OGO4, VlCE2OGO5, and VlCE2OGO6 were down-regulated in response to cold treatments at all tested time points. The 2OG genes can be used for elucidation of mechanisms of tolerance to cold and as valuable molecular genetic resources for selection in breeding programs for cold-hardy grapevines.

Cadmium chloride down-regulates the expression of Rad51 in HC11 cells and reduces knock-in efficiency

  • Ga-Yeon Kim;Man-Jong Kang
    • 한국동물생명공학회지
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    • 제38권3호
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    • pp.99-108
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    • 2023
  • Background: Efficient gene editing technology is needed for successful knock-in. Homologous recombination (HR) is a major double-strand break repair pathway that can be utilized for accurately inserting foreign genes into the genome. HR occurs during the S/G2 phase, and the DNA mismatch repair (MMR) pathway is inextricably linked to HR to maintain HR fidelity. This study was conducted to investigate the effect of inhibiting MMR-related genes using CdCl2, an MMR-related gene inhibitor, on HR efficiency in HC11 cells. Methods: The mRNA and protein expression levels of MMR-related genes (Msh2, Msh3, Msh6, Mlh1, Pms2), the HR-related gene Rad51, and the NHEJ-related gene DNA Ligase IV were assessed in HC11 cells treated with 10 μM of CdCl2 for 48 hours. In addition, HC11 cells were transfected with a CRISPR/sgRNA expression vector and a knock-in vector targeting Exon3 of the mouse-beta casein locus, and treated with 10 μM cadmium for 48 hours. The knock-in efficiency was monitored through PCR. Results: The treatment of HC11 cells with a high-dose of CdCl2 decreased the mRNA expression of the HR-related gene Rad51 in HC11 cells. In addition, the inhibition of MMR-related genes through CdCl2 treatment did not lead to an increase in knock-in efficiency. Conclusions: The inhibition of MMR-related gene expression through high-dose CdCl2 treatment reduces the expression of the HR-related gene Rad51, which is active during recombination. Therefore, it was determined that CdCl2 is an inappropriate compound for improving HR efficiency.

Microbacterium sp. A-210이 생성하는 Levan fructotransferase의 정제 및 생물학적 특성에 관한 연구 (Purification and Biological Characterization of Wild-type and Mutants of a Levan Fructotransferase from Microbacterium sp. AL-210)

  • 황은영;정미숙;차재호;장세복
    • 생명과학회지
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    • 제19권9호
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    • pp.1218-1225
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    • 2009
  • DFA (Difructose anhydride)는 특유의 구조적인 안정성 때문에 당뇨병 환자를 위한 당원으로써 적합하다는 연구가 보고 되어 있다. DFA에는 4가지 type이 있는데 inulin에 의한 DFA I DFA III DFAV가 있고 levan에 의한 DFA IV가 있는 것으로 알려져 있다. 특히 DFA IV는 당뇨병 환자를 위한 당원 뿐 만 아니라 rat을 이용한 연구에서 칼슘의 흡수를 도와 준다는 보고가 있었다. 이러한 DFAIV를 생성하는 데 쓰이는 Microbacterium sp. AL-210에서 유래한 LFTase (Levan fructotransferase)의 wild-type과 mutants (D63A, D195N, N85S)의 구조적 특성을 밝히기 위해 정제하였다. LFTase의 wild-type과 mutants들을 대량 발현시킨 후 흡착 크로마토그래피, 이온교환 크로마토그래피 그리고 젤 여과 크로마토그래피를 이용하여 고순도로 분리 정제하였으며 이를 SDS-PAGE를 통하여 확인하였다. 분리 정제된 단백질을 JNET 이차 구조 예측 프로그램, solubility 측정, CD (원 편광 이색성 분광편광계), fluorescence spectroscopy (형광분석법), DSC (시차주사열량계)를 이용하여 분석하였다. 또한 다중 정렬과 2차 구조 예측 프로그램을 이용하여 wild-type의 2차 구조를 분석하였다. Solubility 측정에서 가장 적합한 온도는 $55^{\circ}C$, 최상의 pH는 7.5로 나타났다. CD 분석에서 wild-type과 비교한 결과 다른 mutant에 비해 N85S의 $\alpha$-helix가 많이 감소한 것과 $\beta$ strand와 random coil이 증가한 것을 확인하였다. 또한 DSC 분석을 통해 wild-type이 다른 mutants에 비해 안정적인 구조를 지닌 것을 확인하였다. 형광분석에서 N85S가 wild-type과 가장 유사하게 나타났으며 D63A와 D195N은 wild-type에 비해 높은 강도를 나타내었다. 또한 wild-type의 sequence를 Exo-inulinase from Aspegillus awamori, a plant fructan 1-exohydrolase from Cichorium intybus 그리고 invertase from Thermotogo maritime (Tm)의 sequence와 다중 정렬한 결과 Exo-inulinase와 높은 identity를 보였다.

PCR-SSCP 분석에 의한 Phytophthora katsurae의 분자생물학적 특성 (Molecular Characteristics of Phytophthora katsurae Using PCR-SSCP Analysis)

  • 이선근;장하나;이동현;이상현;이상용;이종규
    • 식물병연구
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    • 제17권2호
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    • pp.169-176
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    • 2011
  • 우리나라에서 분리한 P. katsurae의 유전적 특성을 구명하기 위하여 국내에서 분리한 P. katsurae를 대상으로 nuclear DNA(nDNA)의 ${\beta}$-tubulin (BTU)과 Elongation facter 1 alpha (EF1A) 그리고 rDNA ITS 부위의 PCR-SSCP 분석을 실시하여, P. katsurae와 Phytophthora 속에 속하는 다양한 종들의 각 부위를 대상으로 유전적 유연관계를 비교분석 하고 동정에 이용하고자 하였다. 각각의 Phytophthora 속에서 변이가 가장 많이 발생하는 부위를 포함하여 증폭 시킬 수 있도록 각 부위의 공통 염기배열로부터 제작된 primer는 Phytophthora 종에 특이적인 반응을 나타냄으로서 동정 및 진단에도 유용하게 활용될 수 있을 것으로 판단되었다. SSCP 분석 결과는 국내 P. katsurae 균주와 공시한 다른 Phytophthora 속 균주들과의 구분이 가능하였으며, Phytophthora 종 간의 구분도 가능하였다. 그러나 한 가지 부위만을 이용한 PCR-SSCP 분석은 Phytophthora 종 간의 구분이 어려운 경우도 있었다. 따라서 보다 정확하고 명확한 Phytophthora 종의 유전적 다양성 분석 및 동정을 위하여서는 단일 부위에 의한 PCR-SSCP보다는 복수 부위에 의한 PCR-SSCP를 실시하는 것이 바람직한 것으로 확인되었다.

Novel Polymorphisms of Adrenergic, Alpha-1B-, Receptor and Peroxisome Proliferator-activated Receptor Gamma, Coactivator 1 Beta Genes and Their Association with Egg Production Traits in Local Chinese Dagu Hens

  • Mu, F.;Jing, Y.;Qin, N.;Zhu, H.Y.;Liu, D.H.;Yuan, S.G.;Xu, R.F.
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권9호
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    • pp.1256-1264
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    • 2016
  • Adrenergic, alpha-1B-, receptor (ADRA1B) and peroxisome proliferator-activated receptor gamma, coactivator 1 beta (PPARGC1B) genes are involved in regulation of hen ovarian development. In this study, these two genes were investigated as possible molecular markers associated with hen-housed egg production, egg weight (EW) and body weight in Chinese Dagu hens. Samples were analyzed using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique, followed by sequencing analysis. Two novel single nucleotide polymorphisms (SNPs) were identified within the candidate genes. Among them, an A/G transition at base position 1915 in exon 2 of ADRA1B gene and a T/C mutation at base position 6146 in the 3'- untranslated region (UTR) of PPARGC1B gene were found to be polymorphic and named SNP A1915G and T6146C, respectively. The SNP A1915G (ADRA1B) leads to a non-synonymous substitution (aspartic acid 489-to-glycine). The 360 birds from the Dagu population were divided into genotypes AA and AG, allele A was found to be present at a higher frequency. Furthermore, the AG genotype correlated with significantly higher hen-housed egg production (HHEP) at 30, 43, 57, and 66 wks of age and with a higher EW at 30 and 43 wks (p<0.05). For the SNP T6146C (PPARGC1B), the hens were typed into TT and TC genotypes, with the T allele shown to be dominant. The TC genotype was also markedly correlated with higher HHEP at 57 and 66 wks of age and EW at 30 and 43 wks (p<0.05). Moreover, four haplotypes were reconstructed based on these two SNPs, with the AGTC haplotype found to be associated with the highest HHEP at 30 to 66 wks of age and with higher EW at 30 and 43 wks (p<0.05). Collectively, the two SNPs identified in this study might be used as potential genetic molecular markers favorable in the improvement of egg productivity in chicken breeding.

Single Nucleotide Polymorphisms of the GnRHR Gene Associated with Reproductive Traits of Japanese Flounder (Paralichthys olivaceus)

  • He, Feng;Wen, Hai-Shen;Li, Ji-Fang;Yu, Da-Hui;Ma, Rui-Qin;Shi, Dan;Mu, Wei-Jie;Zhang, Yuan-Qing;Hu, Jian;Liu, Miao;Han, Wei-Guo;Zhang, Jia-Nan;Wang, Qing-Qing;Yuan, Yu-Ren;Liu, Qun
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권4호
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    • pp.463-470
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    • 2011
  • Gonadotropin-releasing hormone receptor (GnRHR) gene is expressed at the anterior pituitary gland and plays a key role in gonad development. This study aimed to investigate molecular genetic characteristics of the GnRHR gene and elucidate the effects of single nucleotide polymorphisms (SNPs) of GnRHR gene on sex steroid level in Japanese flounder (Paralichthys olivaceus). We used polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequencing of the GnRHR gene in 75 individuals. We identified three SNPs in the GnRHR gene: P1 locus (C759A and C830T) in the coding region of exon2 which were both linked together and P2 locus (G984T) in the coding region of exon3, which added a new transcript factor (ADR1) and a new methylation site (CG). Only C830T of P1 leads to amino acid changes Thr266Ile. Statistical analysis showed that P1 was significantly associated with $17{\beta}$-estradiol ($E_2$) level (p<0.01) and gonadosomatic index (GSI) (p<0.05). Individuals with genotype BB of P1 had significantly higher serum $E_2$ levels (p<0.01) and GSI (p<0.05) than those of genotype AA or AB. Another SNP, P2, synonymous mutation, was significantly associated with GSI (p<0.05). Individuals with genotype AB of P2 had significantly higher GSI (p<0.05) than that of genotype AA. In addition, there was a significant association between one diplotype based on three SNPs and reproductive traits. The genetic effects for both serum $E_2$ level and GSI of diplotype D4 were super diplotypes (p<0.05). These results suggest that the SNPs in Japanese Flounder GnRHR are associated with $E_2$ level and GSI.

비소세포폐암에서 종양억제유전자와 극소위성 변이에 관한 연구 (Genetic Alteration of Tumor Suppressor Gene and Microsatellite in Nonsmall Cell Lung Cancer)

  • 신태림;홍영숙;김진국;장중현
    • Tuberculosis and Respiratory Diseases
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    • 제49권4호
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    • pp.453-465
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    • 2000
  • 연구배경 : 폐암의 발생과정은 다양한 유전자 이상과 여러 가지경로 이상을 포함한 다단계 과정이다. 암유전자의 활성화나 종양억제유전자의 불활성화, 그리고 결과적인 유전적 불안정성의 증가는 폐암의 발암과정에서 일어나는 주요한 사건이며 임상적으로 폐암이 진단되기까지 10내지 20여 가지의 유전적 변화가 축적되는 것으로 알려져 있다. 본 연구에서 저자들은 비소세포폐암에서 종양억제유전자인 p53과 FHIT의 돌연변이, FHIT 유전자의 전사체 이상 여부를 확인하고 종양억제유전자부근에 위치하는 극소위성의 유전적 변화를 관찰하였다. 대상 및 방법 : 비소세포폐암으로 진단된 후 외과적 적출술을 시행받은 환자 29명의 생검조직과 그에 대응하는 동일인의 정상조직을 대상으로 하였다. p53과 FHIT의 돌연변이 여부는 PCR-SSCP, DNA 염기분석으로 확인하였고 D3S1285, D9S171, TP53에서 극소위성 불안정성과 이형접합성 상실은 PCR로 확인하였다. FHIT 유전자의 전사체 이상 여부 확인을 위해서는 RT-PCR을 사용하였다. 결과 : 1) p53 유전자의 2예에서 관찰되었고 모두 exon 5에서 1개의 염기가 치환되는 점돌연변이였다. 2) 극소위성 불안정성은 D3S1285와 D9S171에서 각각 2예, 1예, 이형접합성 상실은 D3S1285, D9S171, TP53에서 각각 3예, 4예, 7예가 관찰되었다. 3) FHIT 유전자의 변이는 11예에서 관찰되었으며 이중 6예는 exon 8의 codon 98에서 염기서열이 CAT가 CAC로 바뀌는 잠재적 치환이었다. 4) FHIT 유전자의 전사체 이상은 $\beta$-actin이 제대로 발현되는 15예중 4예에서 관찰되었으며 exon 6-9의 결실로 확인되었다. 결론 : 이상으로 비소세포폐암 발생에 p53, FHIT 유전자의 변이, 극소위성 불안정성과 이형접합성 상실 등 다양한 분자유전학적 기전이 복합적으로 작용할 것으로 생각되며 이번 연구에서 조사된 유전적 이상의 빈도는 앞서 발표된 서양의 연구결과와 대체적으로 일치한다. 특히 극소위성의 분석은 편평세포암에서 종양표지자로서의 역할이 기대된다. 이런 발암과정에 대한 이해는 예방, 진단 및 치료적 접근을 발전시키는데 도움을 줄 수 있을 것이고 향후 이들에 관한 가능적 연구들이 수행되어야 할 것이다.

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