• Mycobiology
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• 제42권4호
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• pp.422-426
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• 2014

Depending on the acquisition of developmental competence, the expression of genes for ${\beta}$-1,3-glucan synthase and chitin synthase was affected in different ways by Aspergillus nidulans LAMMER kinase. LAMMER kinase deletion, ${\Delta}lkhA$, led to decrease in ${\beta}$-1,3-glucan, but increase in chitin content. The ${\Delta}lkhA$ strain was also resistant to nikkomycin Z.

• Mycobiology
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• 제46권3호
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• pp.236-241
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• 2018

The cation-dependent galactose-specific flocculation activity of the Schizosaccharomyces pombe null mutant of $lkh1^+$, the gene encoding LAMMER kinase homolog, has previously been reported by our group. Here, we show that disruption of $prk1^+$, another flocculation associated regulatory kinase encoding gene, also resulted in cation-dependent galactosespecific flocculation. Deletion of prk1 increased the flocculation phenotype of the $lkh1^+$ null mutant and its overexpression reversed the flocculation of cells caused by lkh1 deletion. Transcript levels of $prk1^+$ were also decreased by $lkh1^+$ deletion. Cumulatively, these results indicate that Lkh1 is one of the negative regulators acting upstream of Prk1, regulating non-sexual flocculation in fission yeast.

• Mycobiology
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• 제51권5호
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• pp.372-378
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• 2023

Lkh1, a LAMMER kinase homolog in the fission yeast Schizosaccharomyces pombe, acts as a negative regulator of filamentous growth and flocculation. It is also involved in the response to oxidative stress. The lkh1-deletion mutant displays slower cell growth, shorter cell size, and abnormal DNA content compared to the wild type. These phenotypes suggest that Lkh1 controls cell size and cell cycle progression. When we performed microarray analysis using the lkh1-deletion mutant, we found that only four of the up-regulated genes in the lkh1-deletion were associated with the cell cycle. Interestingly, all of these genes are regulated by the Mlu1 cell cycle box binding factor (MBF), which is a transcription complex responsible for regulating the expression of cell cycle genes during the G1/S phase. Transcription analyses of the MBF-dependent cell-cycle genes, including negative feedback regulators, confirmed the up-regulation of these genes by the deletion of lkh1. Pull-down assay confirmed the interaction between Lkh1 and Yox1, which is a negative feedback regulator of MBF. This result supports the involvement of LAMMER kinase in cell cycle regulation by modulating MBF activity. In vitro kinase assay and NetPhosK 2.0 analysis with the Yox1T40,41A mutant allele revealed that T40 and T41 residues are the phosphorylation sites mediated by Lkh1. These sites affect the G1/S cell cycle progression of fission yeast by modulating the activity of the MBF complex.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2009년도 International Meeting of the Microbiological Society of Korea
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• pp.127-128
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• 2009

• 미생물학회지
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• 제47권2호
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• pp.110-116
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• 2011

ScKns1는 Saccharomyces cerevisiae에서 발견되는 이중 특이성 인산화 효소이다. S288c 계열에서 $Sckns1{\Delta}$ 균주는 야생형과 차이를 보이지 않아, ScKns1의 세포 내 기능에 대해 밝혀지지 않았다. 그러나 분열 효모에서 LAMMER kinase는 세포 엉김과 균사형 생장 및 산화 스트레스와 관련된 것으로 밝혀졌다. 따라서 형태학적 변화를 관찰할 수 있는 S. cerevisiae ${\Sigma}1278b$ 균주에서 ScKNS1 결손균주($Sckns1{\Delta}$)를 제조하고 표현형 변화를 통하여 기능을 분석하였다. $Sckns1{\Delta}$ 균주는 균사형 생장을 유도하는 질소고갈 조건과 butanol 첨가 조건에서 균사형 생장의 결함을 보였으며, agar 표면의 부착생장도 감소하였다. 또한 $Sckns1{\Delta}$ 균주에 균사형 생장을 조절하는 MAPK 경로 유전자를 도입한 결과 RAS2와 STE20에 의해서는 균사형 생장 결함이 회복되지 않았으나, STE11, STE12와 TEC1에 의해서 결합이 회복되었다. 이러한 결과들은 S. cerevisiae에서도 LAMMER kinase가 MAPK 경로를 통하여 균사형 생장을 조절함을 시사한다.

• Mycobiology
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• 제38권2호
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• pp.108-112
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• 2010

To investigate the possible roles of LAMMER kinase homologue, Lkh1, in Schizosaccharomyces pombe, whole proteins were extracted from wild type and lkh1-deletion mutant cells and subjected to polyacrylamide gel electrophoresis. Differentially expressed proteins were identified by tandem mass spectrometry (MS/MS) and were compared with a protein database. In whole-cell extracts, 10 proteins were up-regulated and 9 proteins were down-regulated in the mutant. In extracellular preparations, 6 proteins were up-regulated in the lkh1+ null mutant and 4 proteins successfully identified: glycolipid anchored surface precursor, $\beta$-glucosidase (Psu1), cell surface protein, glucan 1,3-$\beta$-glucosidase (Bgl2), and exo-1,3 $\beta$-glucanase (Exg1). These results suggest that Lkh1 is involved in regulating cell wall assembly.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.184.2-184
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• 1999

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.202.2-203
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• 2000

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.203.1-203
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• 2000

No Abstract, See Full Text

• 미생물학회지
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• 제47권2호
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• pp.167-169
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• 2011

Saccharomyces cerevisiae ${\Sigma}1278b$ 균주는 FLO8 유전자를 가지고 있는 반면, S288c 균주는 flo8 정지돌연변이를 포함하고 있어서 반수체의 부착 생장, 배수체의 위균사형 생장 및 생물막 형성 현상을 보이지 않는다. S. cerevisiae의 LAMMER kinase인 ScKns1의 기능을 파악하기 위한 온도 감수성 실험을 수행한 결과, S288c 균주와 달리 ${\Sigma}1278b$ 균주가 $37^{\circ}C$의 열 스트레스에 민감함을 발견하였으며, 흥미롭게도 $Sckns1{\Delta}$ 돌연변이가 이러한 감수성을 회복시킴을 확인하였다. 또한 ${\Sigma}1278b$ 균주의 열 감수성은 삼투안정제인 sorbitol의 첨가에 의해 회복되었다. 이러한 결과는 Flo8은 ScKns1이 연관된 열 스트레스를 조절하는 신호전달경로를 구성할 가능성을 제시한다.