• BMB Reports
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• 제34권5호
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• pp.428-433
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• 2001

A defect in uvsC of Aspergillus nidulans caused high methyl methansulfonate (MMS)-sensitivity, hyporecombination, and a lack of UV induced mutation. The uvsC gene of Aspergillus nidulans shares a sequence similarity with the RAD51 gene of Saccharomyces cerevisiae. In this study, in vitro and in vivo tests were conducted in order to determine whether or not the UVSC protein had functional similarities to RAD51, the recombination enzyme in yeast. The purified recombinant UVSC protein, following expression in Escherichia coli, showed binding activity to single-stranded DNA (ssDNA), when both ATP and magnesium are present. In addition, ATPase activity was also demonstrated and its activity was stimulated in the presence of ssDNA. The UVSC protein that was expressed under the ADH promoter in S. cerevisiae suppressed in part the sensitivity to MMS of the rad51 null mutant. Similarly, when the uvsC cDNA was expressed from the nmt promoter, the MMS sensitivity of the rhp51 null mutant of Schizosaccharomyces pombe was partially complemented. These results indicate that the A. nidulans UVSC protein is a functional homologue of the RAD51 protein.

• 미생물학회지
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• 제25권1호
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• pp.57-66
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• 1987

E. coli의 한 변종안 LeB 850 strain을 MNNG되 저해하여 MMS에 대해 증가된 빈감성을 갖는 변종들 분리하다. 이 들에 대해 효소 황동도, 간단한 알켈화제 시약에 대한 띤감성을 조사하고, bacteriophage을 이용한 숙주세포 재활성도 능력 평가 알칼화제 실시하여 이 들을 확정지었다. E. coli의 변종인 5-62뉴 3-methyladenine DNA glycosylase II의 효소 활능도가 전혀 없었으며, 알킬화제 시약인 M:ING와 1\1MS에 대한 매우 증가된 민감성을 보였다. 또한 이 변종 5-62는 MMS가 처리된 phage charon 35-을 숙주내에 셔 새황성화 시키는 능력이 현저히 부족하였다. 변종 5-62에서 MMS에 대해 증가 된 저항성을 주는 MMS+ gene을 cloning 하였다. 재조합 plasmid인 pMRG 1은 변종 5-62에서 MMS에 대한 민감도달 감소시켰으나 MMS에 대한 민감도는 변화 시키시 몫했다. 이 plasmid를 포착한 변종 5-62는 0.5$\mu$g/ml의 MNNG를 $37^{\circ}C$에서 2 시간 처리 하였을때 MMS의 저항성을 보다 촉진시켰다. 재조합 plasmid인 pMRG 1이 alk A 변이와 ada 변이를 회복시키지 못했으나, MMS가 처리된 파지를 재활성화 시키는 능력은 이 plasmid가 없는 변종보다 증가시컸다.

• 미생물학회지
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• 제37권1호
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• pp.28-36
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• 2001

본 연구에서는 세포주기의 Gl/S기에 관련된 유전자의 작용기작을 이해하기 위하여 출아효모인 Saccharomyces cerevisiae를 사용하여 세포주기 진행 및 조절에 관련된 변이주를 분 리하여 특성화하는 연구를 수행하였다. 먼저 새로운 변이주를 분리하기 위해서 HeLa 세포와 출아효모에서 Gl을 유발하는 CPO(ciclopirox olamine) 약제에 대해 감수성을 보이는 변이주를 선별하였다. 그 결과, 총 31개의 CPO에 대한 감수성 변이주들이 분리되었고, ciclopirox olamine sensitivity의 첫 글자를 따서 con mutants라 명명하였다. cos 변이주들의 표현형의 특성을 결정하기 위해 MMS(methylmethane sulfonate)와 HU(hydrsxyurea)에 대한 감수성을 조사하여 그 성질에 따라 4개의 group으로 나누었다. Group I에는 cos27, cos28, cos32, cos33, cos36, cos37, cos40, cos42, cos46, cos50, cos52, cos53 변이주가 포함되고, 이들은 MMS와 HU 두 약제 모두에 대해서 감수성을 보여 S기 checkpoint에 관련된 것으로 보이고, Group II는 cos43, cos48 변이주로 MMS에 대해서 감수성을 지녀 G1기 또는 G2기 checkpoint에 관련된 것으로 추측된다. Group III 변이주에는 cos35, cos47, cos54, cos55, cos56이 포함되고 HU에 대해서 감수성을 보여 S기에 관련된다고 보여지며, Group IV 변이 주는 cos29, cos30, cos31, cos34, cos38, cos39, cos41, cos44, cos45, cos49, cos51, cos57로서 단지 CPO에 대해서만 감수성을 나타냈다. 더욱이 변이주의 최종표현형을 형광현미경을 이용하여 조사하여, S기 checkpoint에 관련된 것으로 보이는 cos37 변이주를 확인하였다. 또한, 변이주와 야생주의 이형접합체인 이배체를 만들어 변이주의 유전학적 분석을 수행하였다.

• 생명과학회지
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• 제17권1호
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• pp.39-44
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• 2007

분열형 효모에서 Rqh1은 Top3과 함께 vegetative growth에 필수적이다. $rqh^-$ 돌연변이는 DNA damaging agent에 민감성을 보이는데 이때, 부적절한 유전자 발현, 세포 신장, 염색체의 불안전성, 비정상적인 다중격막, 발아의 결핍을 포함한 넓은 범위의 표현형을 보인다. rqh1-overexpression cell 역시 rqh1 deletion mutant에서 보이는 DNA damaging agent 민감성을 관찰할 수 있다. 논문은 nmtl promoter를 가지는 PREP vector에 Rqhl이 과발현 할 때 나타나는 DNA damaging agent 민감성를 보상하는 유전자를 찾아 $rqh1^+$의 기능을 알아보는 것이다. 여기서 보상능이 보이는 rqh156, rqh172 두 개의 돌연변이를 골라냈다. rqhl deletion mutant의 DNA damaging agent 민감성은 rqh156, rqh172의 발현에 의해 보상 되어지는 것을 확인하였다.

• Archives of Pharmacal Research
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• 제18권4호
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• pp.243-248
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• 1995

Seventeen transformation-deficient mutants of streptococcus pneumoniae, which are defective in competence induction (com), DNA uptake(ent) of recombination(rec), were investigated to determine sensitivity to ethylmethane sulfonate(EMS), methylmethane sulfonate(MMS), UV and mitomycin C. In ethylmethane sulfonate assay, the viability of most $com^-, \; rec^-\; and ent^-$ mutants was decreased about 2-10 times and the viability of ent-9 and ent-13 mutant was decreased about 33 and 25 times, respectively. On the other hand only half of the transformation-deficient mutants tested was sensitive to methylmethane sulfonate about 2 times and ent-12 mutant was sensitive to 2.0% MMS about 8 times. After UV and mitomycin C treatment, most of the mutants are not sensitive to UV and mitomycin C, although the viability of some transformation-deficient mutants was decreased slightly. Especially none of the com mutants were sensitive to DNA damage suggesting that competence is not involved in DNA repair. Also DNA uptake and recombination gane might be related to DNA repair function.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.258.3-259
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• 2000

No Abstract, See Full Text

• Journal of Microbiology
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• 제39권2호
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• pp.102-108
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• 2001

DNA damage response has a central role in the maintenance of genomic integrity while mutations in related genes may result in a range of disorders including neoplasic formations. The uvsZl characterized in this report is a navel uvs mutation in Aspergillus nidulans, resulting in a nucleotide excision repair (NER) phenotype: UV-sensitivity before DNA synthesis (quiescent cells), high UV-induced mutation frequency and probable absence of involvement with mitotic and meiotic recombinations. The mutation is recessive and nan-allelic to the previously characterized uvsA101 mutation, also located on the paba-y interval on chromosome I. uvsZl skewed wild-type sensitivity to MMS, which suggests non-involvement of this mutation with BER. Epitasis tests showed that the uvsZ gene product is probably involved in the same repair pathways as UVSB or UVSH proteins. Although mutations in these proteins result in an NER phenotype, UVSB is related with cell cycle control and UVSH is associated with the post-replicational repair pathway. The epistatic interaction among uvsZl and uvsB413 and uvsH77 mutations indicates that different repair systems may be related with the common steps of DNA damage response in Aspergillus nidulans.

• 미생물학회지
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• 제38권2호
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• pp.96-102
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• 2002

S기 checkpoint기작은 DNA복제 저해나 DNA상해 등에 반응하여, S기 세포주기 정지를 일으키거나 상해 회복에 관련된 유전자들의 전사가 유도됨으로서 진핵세포에서의 유전적인 안정성을 유지한다. 이러한 반응에 대한것ba11 변이주의 결손을 확인하기 위해서, nPB11 (DNA polymerase B possible subunit)유전자의 과다발현 효과에 대해 조사하고, HU (Hydroxyurea)와 MMS (Methyl methanesulfonate)에 대한 감수성 및 DNA상해 물질에 의한 RNR3 (Ribonulectide reductase) mRNA의 전사 유도를 조사하였다. RNR3 mRNA의 전사는 DNA합성 저해에 의해 발생한 스트레스나 화학물질에 의한 직접적 인 DNA상해 등에 의해 유도되어진다. 그 결과, dpb11-1변이주는 DNA상해 물질에 감수성을 나타내었고, RNR3 mRNA전사유도 또한 야생형 균주에 비해 약 40% 정도 감소를 나타내었다. 더욱이 dpb2-1 균주에서도 이와 동일한 결과를 얻었다. 그러므로 DPB2와 DPB11 유전자는 복제에 대한 sensor로서, 복제 정지 요인에 대한 세포주기 반응과 전사 조절에 모두 작용하는 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.633-643
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• 2017

To examine the pro-apoptotic role of the human ortholog (YPEL5) of the Drosophila Yippee protein, the cell viability of Saccharomyces cerevisiae mutant strain with deleted MOH1, the yeast ortholog, was compared with that of the wild-type (WT)-MOH1 strain after exposure to different apoptogenic stimulants, including UV irradiation, methyl methanesulfonate (MMS), camptothecin (CPT), heat shock, and hyperosmotic shock. The $moh1{\Delta}$ mutant exhibited enhanced cell viability compared with the WT-MOH1 strain when treated with lethal UV irradiation, 1.8 mM MMS, $100{\mu}M$ CPT, heat shock at $50^{\circ}C$, or 1.2 M KCl. At the same time, the level of Moh1 protein was commonly up-regulated in the WT-MOH1 strain as was that of Ynk1 protein, which is known as a marker for DNA damage. Although the enhanced UV resistance of the $moh1{\Delta}$ mutant largely disappeared following transformation with the yeast MOH1 gene or one of the human YPEL1-YPEL5 genes, the transformant bearing pYES2-YPEL5 was more sensitive to lethal UV irradiation and its UV sensitivity was similar to that of the WT-MOH1 strain. Under these conditions, the UV irradiation-induced apoptotic events, such as FITC-Annexin V stainability, mitochondrial membrane potential (${\Delta}{\psi}m$) loss, and metacaspase activation, occurred to a much lesser extent in the $moh1{\Delta}$ mutant compared with the WT-MOH1 strain and the mutant strain bearing pYES2-MOH1 or pYES2-YPEL5. These results demonstrate the functional conservation between yeast Moh1 and human YPEL5, and their involvement in mitochondria-dependent apoptosis induced by DNA damage.

• Animal cells and systems
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• 제3권2호
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• pp.229-236
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• 1999

The recA gene plays a central role in genetic recombination and SOS DNA repair in Escherichia coli (E. coli). We have previously identified a 42 kDa RecA-like protein inducible by a variety of DNA damages from a fluorescent Pseudomonas strain sp. and characterized its inducible kinetics. In the present study, we cloned and characterized the gene encoding the RecA-like protein by immunological screening of Pseudomonas genomic expression library using polyclonal E. coli anti-RecA antibodies as a probe. From 10$^{5}$ plaques screened, five putative clones were finally isolated. Southern blot analysis indicated that four clones had the same DNA inserts and the recA-like gene was located within the 3.2 kb EcoRI fragment of Pseudomonas chromosomal DNA. In addition, the cloned recA-like gene was transcribed into an RNA transcript approximately 1.1 kb in size, as judged by Northern blot analysis. The cellular level of RNA transcript of the cloned recA-like gene was increased to an average of 5.15- fold upon treatment with DNA damaging agents such as ultraviolet (UV)- light, nalidixic acid (NA), methyl methanesulfonate (MMS), and mitomycin-C (MMC). These results suggest that the cloned gene is inducible by DNA damage similarly to the recA gene in E. coli. However, the cloned gene did not restore the DNA damage sensitivity of the E. coli recA-mutant.