• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.6-14
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• 2022

Brucella spp. are facultative intracellular pathogens that invade, survive and proliferate in numerous phagocytic and non-phagocytic cell types, thereby leading to human and animal brucellosis. Outer membrane proteins (Omps) are major immunogenic and protective antigens that are implicated in Brucella virulence. A strain deleted of the omp16 gene has not been obtained which suggests that the Omp16 protein is vital for Brucella survival. Nevertheless, we previously constructed an omp16 conditional deletion strain of Brucella, ∆Omp16. Here, the virulence and immune response elicted by this strain were assessed in a mouse model of infection. Splenomegaly was significantly reduced at two weeks post-infection in ∆Omp16-infected mice compared to infection with the parental strain. The bacterial load in the spleen also was significantly decreased at this post-infection time point in ∆Omp16-infected mice. Histopathological changes in the spleen were observed via hematoxylin-eosin staining and microscopic examination which showed that infection with the ∆Omp16 strain alleviated spleen histopathological alterations compared to mice infected with the parental strain. Moreover, the levels of humoral and cellular immunity were similar in both ∆Omp16-infected mice and parental strain-infected mice. The results overall show that the virulence of ∆Omp16 is attenuated markedly, but that the immune responses mediated by the deletion and parental strains in mice are indistinguishable. The data provide important insights that illuminate the pathogenic strategies adopted by Brucella.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2007년도 정기학술대회
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• pp.394-404
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• 2007

This paper explores the nature of multiple sluicing in English, which has two or more remnant wh-phrases in clause edge position. At the beginning part of the paper we argue against Nishigauchi's (1998) and Lasnik's (2007) Gapping analysis of multiple sluicing, which says that two remnant wh-phrases each actually occupies the left and right edge of a clause, with the in-between string of words undergoing Gapping. We rather argue that multiple sluicing in English is the same kind as found in Bulgarian and Serbo-Croatian. In other words, multiple sluicing in English is also derived by multiple wh-fronting which otherwise does not apply. We demonstrate that some important properties of the construction noted by Lmultiple sluicing, multiple wh-movement/fronting, sluicing, TP/IP-deletion, asnik (2007) under the Gapping approach to it can be accounted for in a principled way by our proposed analysis.

• Plant Biotechnology Reports
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• 제4권1호
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• pp.29-35
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• 2010

NPR1 is a positive regulator of systemic acquired resistance in Arabidopsis and rice. Expression of the rice gene OsNPR1 is induced by salicylic acid (SA). To identify the region of the OsNPR1 promoter involved in response to SA, we carried out deletion mutagenesis of the region 1005 bp upstream of the OsNPR1 start codon. Ciselement analysis revealed that the OsNPR1 promoter contains W-boxes and ASF1 motifs, both of which are known to be functional cis-elements of the WRKY and bZIP proteins, respectively. The deletion constructs 1005:LUC and 752:LUC, were induced by up to 4.3- and 3.8-fold, respectively, following SA treatment, suggesting that W-boxes and ASF1 motifs may play an important role in the strong induction of these constructs by SA. Using mutation analysis, we also showed that both the W-box and ASF1 motif are necessary for SA-induced expression of OsNPR1.

• BMB Reports
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• 제41권11호
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• pp.778-783
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• 2008

Turnip yellow mosaic virus (TYMV) RNA has two hairpins in its 5' untranslated region (5'-UTR). To investigate the role of the hairpins in replication of TYMV, mutants lacking one or both of the two hairpins were constructed. The TYMV constructs were introduced into Chinese cabbage by an Agrobacterium-mediated T-DNA transfer method, called agroinfiltration. Analysis of total RNA from agroinfiltrated leaves showed that replication of the mutant TYMV RNA lacking both hairpins was about 1/100 of wild type. This mutant was also impaired in systemic spread. Deletion analysis of each hairpin revealed that both hairpins were needed for maximal replication. The deletion analysis along with sequence modification of the hairpin structure indicates that the second hairpin plays a role in efficient long-distance systemic movement of TYMV.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1336-1342
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• 2012

In Burkholderia pseudomallei, the pathogen that causes melioidosis, the gene cluster encoding the capsular polysaccharide, is located on chromosome 1. Among the 19 capsular genes in this cluster, wzm has not been thoroughly studied. To study the function of wzm, we generated a deletion mutant and compared it with the wild-type strain. The mutant produced less biofilm in minimal media and was more sensitive to desiccation and oxidative stress compared with the wild-type strain, indicating that wzm is involved in biofilm formation and membrane integrity. Scanning electron microscopy showed that the bacterial cells of the mutant strain have more defined surfaces with indentations, whereas cells of the wild-type strain do not.

• 미생물학회지
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• 제40권2호
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• pp.87-93
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• 2004

세포질과 핵단백질의 serine과 threonine 잔기에 O-linked N-acetyl-$\beta$-glucosamine (O-GlcNAc)의 첨가는고등 진핵 세포에서 흔히 일어나는 번역 후 단백질의 변형 중 하나로서 단백질의 인산화와 유사한 세포 내 신호전달에 관여하는 것으로 보인다. O-GlcNAc의 첨가와 제거는 O-GlcNAc transferase (OGT)와 O-linked N-acetyl-$\beta$-D-glucos-aminidase (O-GlcNAcase) 효소에 의해 각각 촉매된다. 두가지 종류의 사람 유래 O-GlcNAcase 유전자(O-GlcNAcase, v-O-GlcNAcase)를cloning하고 세 가지의 융합단백질로 대장균에서 생산을 시도하였다. O-GlcNAcase의 기질 유사체 인 ${\rho}$-nitrophenyl-N-acetyl-$\beta$-D-g1ucosaminide (${\rho}$NP-$\beta$-D-GlcNAc)를 기질로 사용하여 효소활성을 측정 한 결과 v-O-GlcNAcase는 활성을 나타내지 않았다. 여러 종류의 amino sugar 기질 유사체를 사용하여 O-GlcNAcase의 활성을 측정하였으나 오직 ${\rho}$NP-$\beta$-D-GlcNAc만이 활성을 보였다. Blast검색으로 분석한 결과 아미노 말단의 hyaluronidase-like domain (hyaluronidase-유사 영역)과 카르복시 말단의 N-acetyltransferase 영역 두 곳의 conserved domains 존재하였다. 효소촉매에 중요한 영역을 밝히기 위해 여러 deletion mutants(결손 변이체)를 제작한 후 효소활성을 측정하고 Western blot으로 분석하였다. Hyaluronidas-유사 영역, 유전자 내부와 N-acetyltransferase 영역을 제거할 경우 효소활성이 사라졌으나 아미노 말단의 55개 아미노산과 카르복시 말단의 truncation은 활성을 일부분 유지하였다. 위의 사실에 기초하여 hyaluronidas-유사 영역은 효소활성에 중요하고 카르복시 말단의 N-acetyltransferase 영역은 조절기능으로 작용하는 것으로 추정된다.

• 한국미생물·생명공학회지
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• 제34권3호
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• pp.278-287
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• 2006

토양으로부터 분리한 P. polymyxa 균주가 생산하는 CFTase의 각 repeat region의 결손 변이체를 제작하였으며 그에 따른 야생형 효소와 변이 효소의 활성변화 및 효소특성을 비교 검토하였다. 야생형 CFTase를 CFT148로, N-말단의 R1과 R3를 제거한 결손변이체 CFTase를 CFT108로, C-말단의 R4를 제거한 결손변이체는 CFT130, 모든 R 영역을 제거한 것은 CFT88로 명명하였다. 각각 정제된 재조합 단백질은 148 kDa, 108 kDa, 130 kDa, 그리고 88 kDa의 크기를 나타내었다. Inulin을 기질로 각 재조합 단백질의 활성을 검토한 결과 CFT108은 CF생성, CF분해 반응을 모두 가지고 있었으며 CFT130, CFT88의 경우에는 CF생성 활성을 나타내지 않았으며 endo-inulinae와 동일한 inulin 분해활성을 나타내었다. 따라서 N-말단의 repeat region인 R1과, R3의 역할은 균체 외로의 분비를 담당하며 C-말단의 R4영역은 CFTase의 중요 활성인 cyclization반응을 담당하고 있는 것으로 확인되었다. Repeat region의 모두 제거한 결손 변이체는 기질 inulin을 F2-F4 사이의 중합도를 가진fructooligosaccharide를 생산하는 endo-inulinase의 활성을 가지고 있었다. CFTase는 다기능 효소로 여러 domain으로 구성되어 있으며 각 domain의 결손에도 단백질의 활성을 유지하였으며, 특히 결손 변이체 CFT108은 고효율의 CF 생산이 가능하여 산업적으로 유용하게 사용될 수 있는 효소이다.

• 인문언어
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• 제8집
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• pp.265-289
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• 2006

The geographical characteristics of Yeongdong(永同) the southernmost part of the Chungcheongbukdo province, has attracted attention among the academic circle as one of the dialectal contact regions since it adjoins the Gyeongsang and Jeolla dialects. Unlike the local language in Mooju (Jellado dialect) adjacent to the Southwest part, the local language in Yeongdong is quite different from that of Kimcheon (Gyeongsang dialect). More specifically, it is noteworthy that the boundary line of the Gyeongsang dialect is found in this region, which is different from the administrative division. In other words, the local language in Yeongdong is divided into the Chungcheong dialect and the Gyeongsang dialect, and furthermore each dialect region still has the characteristics of the other region's dialect. For example, the phonological structure of Yeongdong Chungcheongdo dialect has very unique characteristics of the fudged dialect, which is seemingly influenced by the Gyeongsang dialect. The present study is to define the bottom boundary line of the southeast area of the Chungcheong dialect by identifying the boundary line between the Gyeongsang dialect and the Chungcheong dialect, and to clarify its specific sound system generated by the contact of these two dialects. For this, the author collected and analyzed data of the local language around Yeongdong and adjacent areas. It was found that Cheongwha-ri, Deokjin-ri, and Sanjeo-ri at Yeongsan-myeon, and Mugeunjeom, Sangga-ri, and Jungga-ri at Yeongdong-eup, among the regions that belongs to Chungcheong dialect within the local language of Yeongdong, show the characteristics of the Gyeongsang dialect. Accordingly, the western areas of these villages become the southeast boundary line of the Chungcheong dialect. Also, the unique phonological characteristics of the Yeongdong Chungcheong dialect is affected by the Gyeongsang dialect, among which "rhythms, y deletion, nasal phoneme deletion, and w deletion" appeared. It is thought to be the unique fudged dialectal phenomenon that appeared only in this region. The research result is expected to be of some help in finding out various aspects of dialectal contacts as well as clarifying the phonological features of the local language in Yeongdong, and thereby contributing to exact divisioning of the Chungcheong dialect.

• BMB Reports
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• 제49권6호
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• pp.337-343
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• 2016

Understanding of trafficking, processing, and degradation mechanisms of amyloid precursor protein (APP) is important because APP can be processed to produce β-amyloid (Aβ), a key pathogenic molecule in Alzheimer's disease (AD). Here, we found that APP contains KFERQ motif at its C-terminus, a consensus sequence for chaperone-mediated autophagy (CMA) or microautophagy which are another types of autophagy for degradation of pathogenic molecules in neurodegenerative diseases. Deletion of KFERQ in APP increased C-terminal fragments (CTFs) and secreted N-terminal fragments of APP and kept it away from lysosomes. KFERQ deletion did not abolish the interaction of APP or its cleaved products with heat shock cognate protein 70 (Hsc70), a protein necessary for CMA or microautophagy. These findings suggest that KFERQ motif is important for normal processing and degradation of APP to preclude the accumulation of APP-CTFs although it may not be important for CMA or microautophagy.

• Mycobiology
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• 제47권4호
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• pp.457-465
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• 2019

MonA is a subunit of a guanine nucleotide exchange factor that is important for vacuole passing and autophagy processes in eukaryotes. In this study, we characterized the function of MonA, an orthologue of Saccharomyces cerevisiae Mon1, in the model fungus Aspergillus nidulans and a toxigenic fungus A. flavus. In A. nidulans, the absence of AnimonA led to decreased fungal growth, reduced asexual reproduction, and defective cleistothecia production. In addition, AnimonA deletion mutants exhibited decreased spore viability, had reduced trehalose contents in conidia, and were sensitive to thermal stress. In A. flavus, deletion of AflmonA caused decreased fungal growth and defective production of asexual spores and sclerotia structures. Moreover, the absence of monA affected vacuole morphology in both species. Taken together, these results indicate that MonA plays conserved roles in controlling fungal growth, development and vacuole morphology in A. nidulans and A. flavus.