• 미생물학회지
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• 제31권3호
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• pp.197-202
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• 1993

출아법으로 분열하는 S. cerevisiae 는 mother cell 과 bud cell 과의 연결부위근처의 원형질막 내부에 10-nm filament ring 이 존재한다. CDC3, CDC10, CDC11, CDC12 유전자가 이 filament 를 암호화할 가능성이 많은 것으로 알려져 있으며, 근래에 CDC3 와 CDC12 유전자의 생성물들이 filament ring 에 존재한다는 것이 형광현미경을 이용하여 밝혀졌으나 그 기능은 밝혀지지 않았다. 이에 본인은 10-nm filament ring 의 지능을 알아보기 위하여 ring을 이루고 있는 S. cerevisiae 의 CDC3유전자와 유사한 S. pombe 유전자의 clone 을 시도하였다. 이를 위하여 .lambda. gt11 expression vector 에 S. pombe genomic library 를 만들고 CDC3 항채를 이용하여 screen 하였다. Screen 된 유전자를 sequencing 하여 본 결과, 2개 이상의 intron 이 존재하는 것이 밝혀졌으나, 일부 부위의 아미노산 서열과 CDC3 아미노산 서열을 비교하여 본 결과, 약 62%의 유사성이 존재하였다.

• Journal of Microbiology
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• 제33권4호
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• pp.350-354
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• 1995

Saccharomyces cervisiae has a highly ordered ring of filaments that lies just inside the cytoplasmic membrane in the region of the mother-bud neck. Mutants defective in any one of the our cell division cycle genes (CDC3, CDC10, CDC11, CDC12) fail to form these filaments and exhibit a pleiotropic phenotype that includes failure to complete cytokinesis and abnormal bud growth. However, the role of the filament is not clear. In order to find out the role of filament, the similar gene in S pombe (called cdc103$\^$+) to the CDC3 was cloned and sequenced. Here I report the sequence analysis of the cdc103$\^$+/ ) to the CDC3 was cloned and sequenced. Here I report the sequence analysis of the cdc103$\^$+/. Comparison of the predicted amino acid sequences of cdc103$\^$+/ and CDC3 revealed that they share significant similarity (43% identity and 56% identity or similarity) to each other.

• Molecules and Cells
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• 제40권12호
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• pp.925-934
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• 2017

The Cdc6 protein is essential for the initiation of chromosomal replication and functions as a licensing factor to maintain chromosome integrity. During the S and G2 phases of the cell cycle, Cdc6 has been found to inhibit the recruitment of pericentriolar material (PCM) proteins to the centrosome and to suppress centrosome over-duplication. In this report, we analyzed the correlation between these two functions of Cdc6 at the centrosome. Cdc6 depletion increased the population of cells showing centrosome over-duplication and premature centrosome separation; Cdc6 expression reversed these changes. Deletion and fusion experiments revealed that the 18 amino acid residues (197-214) of Cdc6, which were fused to the Cdc6-centrosomal localization signal, suppressed centrosome over-duplication and premature centrosome separation. Cdc6 mutant proteins that showed defective ATP binding or hydrolysis did not exhibit a significant difference in suppressing centrosome over-duplication, compared to the wild type protein. In contrast to the Cdc6-mediated inhibition of PCM protein recruitment to the centrosome, the independence of Cdc6 on its ATPase activity for suppressing centrosome over-duplication, along with the difference between the Cdc6 protein regions participating in the two functions, suggested that Cdc6 controls centrosome duplication in a manner independent of its recruitment of PCM proteins to the centrosome.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1755-1756
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• 2004

• 미생물학회지
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• 제30권5호
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• pp.333-338
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• 1992

Saccharomyces cerevisiae 의 mother cell과 daughter cell 의 연결 부위의 원형질막 바로 안쪽에 존재하는 10-nm filament ring 은 세포형태 형성과정에 중요한 역할을 하리라 간주되나 그 명확한 생성기작과 기능은 밝혀지지 않았다. 본연구에서는 CDC12 유전자로부터 gene fusion technique 을 이용하여 CDC12 단백질을 만들고 이로부터 항체를 형성하였다. 이항체를 이용하여 10-nm filament ring 의 생성기작과 기능에 대하여 연구하였다. 그 결과 CDC12 단백질은 cell cycle 전주기동안 항상 정이되나 bud 가 나오기 바고 직전에 bud 가 나올 부위에 polymerization 되었다가 세포질분열 바로 직후에 unpolymerization 되며 cytoskeletal element 의 일종인 actin 과는 무관하게 행동하는 건이 밝혀졌다. 이러한 10-nm filament 는 bud 가 나올 부위의 올바른 선정과 세포질 분열에 중요한 역할을 하리라 간주된다.

• BMB Reports
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• 제41권12호
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• pp.852-857
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• 2008

Little attention has been paid to the specificity between E2 and the target protein during ubiquitination, although RING-E3 induces a potential intra-molecular reaction by mediating the direct transfer of ubiquitin from E2 to the target protein. We have constructed artificial E2 fusion proteins in which a target protein (p27) is tethered to one of six E2s via a flexible linker. Interestingly, only three E2s (UbcH5b, hHR6b, and Cdc34) are able to ubiquitinate p27 via an intra-molecular reaction in this system. Although the first ubiquitination of p27 (p27-Ub) by Cdc34 is less efficient than that of UbcH5b and hHR6b, the additional ubiquitin attachment to p27-Ub by Cdc34 is highly efficient. The E2 core of Cdc34 provides specificity to p27, and the residues 184-196 are required for possessive ubiquitination by Cdc34. We demonstrate direct E2 specificity for p27 and also show that differential ubiquitin linkages can be dependent on E2 alone.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제15권1호
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• pp.29-37
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• 2012

Purpose: To examine the prevalence of $Clostridium$ $difficile$ ($C.$ $difficile$) colonization (CDC) and potential neonatal determinants of CDC in hospitalized preterm infants. Methods: Fecal samples were serially collected within 72 h after birth and at 1, 2, and 4-6 weeks of age from preterm infants in the neonatal intensive care units (NICUs) of two different university hospitals. Total bacterial DNA was extracted from each fecal sample from 49 infants, and polymerase chain reaction (PCR) was performed with primers for the 16S gene of $C.$ $difficile$ and the toxin A and toxin B genes. The correlation between the results of $C.$ $difficile$ PCR assays and the clinical characteristics of the infants was analyzed. Results: The prevalence rates of CDC were 34.7, 37.2, 41.3, and 53.1% within 72 h after birth and at 1, 2, and 4.6 weeks of age, respectively. The toxin positivity rate was significantly higher in the infants with persistent CDC than in those with transient CDC (8/12 [66.7%] vs. 6/25 [24.5%] ($p$=0.001). Among the various neonatal factors, only the feeding method during the first week after birth was significantly associated with persistent CDC. Exclusive breast-milk feeding (EBMF) significantly decreased the risk of persistent CDC compared to formula or mixed feeding (adjusted odds ratio: 0.133, 95% confidence interval: 0.02-0.898, $p$=0.038). Conclusion: The prevalence of CDC increased with the duration of hospitalization in preterm infants in the NICU. EBMF during the first week after birth in hospitalized preterm infants may protect against persistent CDC.

• 한국균학회지
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• 제19권4호
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• pp.266-275
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• 1991

효모의 mating pheromone에 의한 세포내 Slgnal을 전달하는 물질을 coding 하거나 조절할 수 있는 유전자에 대한 정보를 얻기 위해서 효모에서 G-protein의 ${\alpha}-subunit$를 coding 하는 유전자 CDC70에 돌연변이가 얼어난 균주 $A14-3(MAT{\alpha},\;cdc70-5)$에 UV를 조사하여 돌연변이 cdc70-5를 억제할수 있는 또 다른 돌연변이를 획득하였다 . 돌연변이 cdc70-5의 표현형은 온도 감수성 (temperature sensitivity)이며, $38^{\circ}C$에서 배양하면 세포주기가 G1에서 정지되고 shmoo모양을 보인다 . 균주 A14-3에서 UV를 조사하였을 때 $38^{\circ}C$에서 colony를 형성할 수 있고 세포분열이 정상적으로 진행되어 출아를 하고 있다는 것은 새로운 돌연변이가 cdc70-5 의 표현형을 억제 한다는 사실을 의미한다 . 이러한 억제돌연변이 중 signal transducer와 직접적으로 관련이 없는 유전자들인 $sir^-$ 및 $mat{\alpha}2^-$ 돌연변이를 배제한 다음 선택된 15개의 돌연변이들를 중심으로 분석을 행하였다 . 어느 유전자에서 유발 되었는지 그리고 유전자 종류는 몇 가지나 되는지를 암기 위하여 tetrad analysis를 통해 연관여부를 조사하여 분리된 15개의 돌연변이중 12개는 4개의 연관군(sga1, sga2, sga3, sga4)에 속함을 알았다.

• 한국환경성돌연변이발암원학회지
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• 제21권2호
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• pp.82-88
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• 2001

Recently, there has been significant progress in understanding the control process of the cell division cycle. To investigate the influence of toxic substances on the cell cycle, the effect of benzo(a)pyrene (BAP) and mitomycine C (MMC) on synchronized HeLa cells was analyzed during the cell cycle. To synchronize the HeLa cells, 10$^{6}$ cells were grown for 1 day and then treated with 1 mM hydroxyurea for 14 h. The arrested cells were then allowed to proceed through their cell cycle by removing the hydroxyurea and resupplying a fresh medium. The arrested cells in the G1/S transition then proceeded to the S phase after 4 h, the G2/M phase after 8h, and the G1 phase after 12 h, subsequent to the resupply of a fresh medium. In the untreated HeLa cells, the p34$^{cdc2}$ kinase activity, measured using a p34$^{cdc2}$ specific peptide, peaked after 8h (G2/M) and then declined after 12 h (G1). However, treatment with 30 $\mu$M BAP delayed the peak of the p34$^{cdc2}$ kinase activity. The amount of p34$^{cdc2}$ remained unchanged in the untreated, BAP-, and MMC-treated cells throughout the cell cycle. The cyclin B level peaked after 8 h in the untreated cells, yet peaked after 10-12 h in the BAP-treated cells. There was no significant change in the cyclin B level in the MMC-treated cells.

• Journal of Microbiology
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• 제45권3호
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• pp.227-233
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• 2007

In budding yeast, septin plays as a scaffold to recruits protein components and regulates crucial cellular events including bud site selection, bud morphogenesis, Cdc28 activation pathway, and cytokinesis. Phosphorylation of Bni5 isolated as a suppressor for septin defect is essential to Swe1-dependent regulation of bud morphogenesis and mitotic entry. The mechanism by which Bni5 regulates normal septin function is not completely understood. Here, we provide evidence that Bni5 phosphorylation is important for interaction with septin component Cdc11 and for timely delocalization from septin filament at late mitosis. Phosphorylation-deficient bni5-4A was synthetically lethal with $hof1{\Delta}$. bni5-4A cells had defective structure of septin ring and connected cell morphology, indicative of defects in cytokinesis. Two-hybrid analysis revealed that bni5-4A has a defect in direct interaction with Cdc11 and Cdc12. GFP-tagged bni5-4A was normally localized at mother-bud neck of budded cells before middle of mitosis. In contrast, at large-budded telophase cells, bni5-4A-GFP was defective in localization and disappeared from the neck approximately 2 min earlier than that of wild type, as evidenced by time-lapse analysis. Therefore, earlier delocalization of bni5-4A from septin filament is consistent with phosphorylation-dependent interaction with the septin component. These results suggest that timely de localization of Bni5 by phosphorylation is important for septin function and regulation of cytokinesis.