• 한국균학회지
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• 제10권2호
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• pp.57-65
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• 1982

경정곰팡이(Aspergillus niger)의 포자형성(胞子形成)을 액침배양법(液浸培養法)과 동조적방법(同調的方法)으로 여행(旅行)하면서 인산화합물(燐酸化合物), 고인산화(高燐酸化)뉴크레오티드, 및 RNA(핵산)(核酸)의 동태(動態)를 연구(硏究)하였다. 결과(結果)는 다음과 같이 요약(要約)된다. 1. 곰팡이의 포자형성시(胞子形成時)에 유기인산화합물(有機燐酸化合物)의 양(量)이 증가(增加)하였으며, 무기(無機) Polyphosphate의 양(量)은 반대(反對)로 감소(減少)하였다. 2. 무기인산양(無機燐酸量)은 변동(變動)하지 않았으며, 총인산화합물(總燐酸化合物)의 양(量)은 초기균사생장시(初期菌絲生長時)에는 감소(減少)하고 포자낭병시기(胞子囊柄時期)부터는 변동(變動)하지 않았다. 3. RNA핵산구획(核酸區劃)에 있어서 orcinol 반응양성구(反應陽性區)의 흡광도(吸光度)가 급격(急激)히 증가(增加)하였다. 그러나 UV흡광도(吸光度)는 완만하게 증가(增加)하였다. 4. 포자낭병(胞子囊柄)및 포자형성시기(胞子形成時期)에 guanosinetetraphosphate가 검출현(檢出現) 되었다. 5. 고분자양성(高分子量性) RNA (rRNA분획(分劃))의 polyacrylamide gel 전기영동(電氣泳動)을 2.6% gel로서 시행(施行)한 바 polyphosphate와 RNA의 결합물(結合物)이 상당양(相當量) 존재(存在)함을 알았다. 이상(以上)의 결과(結果)로 보아 검정곰팡이의 분화과정(分化過程)에 있어서 고인산화(高燐酸化) RNA 화합물(化合物)의 존재(存在)가 확인(確認)되었으며, 이 화합물(化合物) 가운데 guanosine tetraphosphate (G4P)의 존재(存在)가 진핵미생물(眞核微生物)인 곰팡이에서도 검출(檢出)되었음을 지적(指摘)한다.

• 한국균학회지
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• 제12권4호
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• pp.141-152
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• 1984

1. 검정곰팡이 (Aspergillus niger)를 실험재료로 하여 동조적으로 액침배양한 결과 포자의 발아로 부터 균사의 생장, 생식기관의 성숙 및 무성포자의 형성까지를 재현시킬 수 있었다. 2. 각 분화과정에서의 균체로 부터 고인산화뉴를레오티드를 추출하여 P.E.I. Cellulose TLC법으로 전개시켰다. 3. 포자형성 직전의 균체로 부터 얻은 추출물 중에 구아노신테트라포스페이트 $(GP_4)$가 존재함을 확인하였다. 4. 분화과정에 따른 균체로부터 추출한 유리아미노산의 총량은 포자형성 직전에 급격히 증가함을 알았다. 5. 정낭과 경자가 완성된 균체에 8-아자구아닌과 시클로헥시미드를 처리한 바 포자형성이 억제되었다. 6. 전낭과 경자가 완성된 균체에 이노신산과 구아닌산을 처리한 바 포자형성이 촉진되었다.

• Journal of Veterinary Science
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• 제23권2호
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• pp.28.1-28.18
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• 2022

Enteropathogenic Escherichia coli (EPEC) is a major cause of infantile diarrhea in developing countries. However, sporadic outbreaks caused by this microorganism in developed countries are frequently reported recently. As an important zoonotic pathogen, EPEC is being monitored annually in several countries. Hallmark of EPEC infection is formation of attaching and effacing (A/E) lesions on the small intestine. To establish A/E lesions during a gastrointestinal tract (GIT) infeciton, EPEC must thrive in diverse GIT environments. A variety of stress responses by EPEC have been reported. These responses play significant roles in helping E. coli pass through GIT environments and establishing E. coli infection. Stringent response is one of those responses. It is mediated by guanosine tetraphosphate. Interestingly, previous studies have demonstrated that stringent response is a universal virulence regulatory mechanism present in many bacterial pathogens including EPEC. However, biological signficance of a bacterial stringent response in both EPEC and its interaction with the host during a GIT infection is unclear. It needs to be elucidated to broaden our insight to EPEC pathogenesis. In this review, diverse responses, including stringent response, of EPEC during a GIT infection are discussed to provide a new insight into EPEC pathophysiology in the GIT.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.69.1-69
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• 2003

RSH (relA/spoT homolog) has been known to determine the level of guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp), which are the effector nucleotide of the prokaryotic stringent response and also play a role in antibiotic production and differentiation in Streptomyces species but not a little in eukaryotic organism, especially in plant. Salicylic acid (SA), a critical signal molecule of establishing systemic acquired resistance (SAR), could induce SAR in Pepper (Capcicum annuum) against Phytophthora capsici. And the extent of SAR induction was in proportion to the dosage of SA (or BTH). Suppression subtractive hybridization (SSH), a PCR-based method for cDNA subtraction, was carried out between SA-treated and non-SA-treated pepper leaves to isolate genes which may be responsible for defense signaling against pathogens. Early upregulated gene was selected from reverse northern and kinetics of SSH-genes transcripts in SA-treated pepper leaves upon SA treatment. Full-length cDNA of the gene (PepRSH； Pepper RelA / SpoT homolog) had an open reading frame (ORF) of 2166 bp encoding a protein of 722 amino acids and a significant homology with (p)ppGpp phosphohydrolase or synthetase. Genomic DNA gel blot analysis showed that pepper genome has at least single copy of PepRSH. PepRSH transcripts was very low in untreated pepper leaves but strongly induced by SA and methyljasmonic acid (MeJA), indicating that PepRSH may share common SA and MeJA-mediated signal transduction pathway Functional analysis in E. coli showed PepRSH confers phenotypes associated with (p)ppGpp synthesis through a complementation using active site mutagenesis.