• 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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• 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.

• 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.

• 한국운동역학회지
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• 제21권3호
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• pp.269-279
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• 2011

This study was analyzed the characteristics on the stability of posture while conducting a through two and half rotation technic of pench$\acute{e}$ in rhythmic gymnastics. Two rhythmical gymnastics player(LKH and SSJ) who is a member of the national team were selected, and for obtain the kinematic and kinetic variables were used a ProReflex MCU 240 infrared camera(Qualisys, Sweden) and a Type9286A force platform(Kistler, Switzerland). The mechanical factors were computed by using Visual3D program and Matlab R2009a. During the landing and rotation phase the results showed following characteristics; 1) In medial-lateral and horizontal displacement of the support foot, LKH showed smaller movement than SSJ, but SSJ showed smaller movement than LKH in swing foot. LKH showed bigger movement in medial-lateral axis of COP and vertical axis of COG, but SSJ showed bigger movement in horizontal axis of COP and medial-lateral axis of COG. 2) SSJ showed bigger maximum horizontal and vertical velocity at P1 and P2 than LKH. 3) In the inclination angle of COP and COG, SSJ showed smaller change than LKH, but within medial-lateral tilt of the shoulder, LKH performed rotation motion in horizontal position than SSJ. There was no differences in each force components during rotation, but on landing phase, the results showed a characteristic that SSJ exerted bigger breaking force and vertical force than LKH.

• 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.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2010년도 추계학술발표대회
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• pp.1158-1161
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• 2010

사용자 그룹 서비스는 IPTV를 비롯한 다양한 분야에 걸쳐 응용되고 있으며, 안전한 그룹 통신을 위해 그룹 키를 사용한다. 그룹 키 관리를 보다 효율적으로 하기 위해 최근 많은 연구에서 트리를 이용한 기법을 제시하였다. 그 중 대표적인 기법은 LKH, OFT 등이 있으며, 이들은 그룹 키를 갱신하는데 필요한 메시지 전송량이 O(lgN) 수준이다. 이후 Sun, Kang 등은 키 갱신에 필요한 메시지 전송량을 O(1) 수준으로 감소시켜 더욱 효율적인 기법을 제안하였다. 본 논문에서는 이와 같은 기법들을 비교분석하여 효율성과 안전성에 대해 재조명하였다.

• 정보처리학회논문지C
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• 제16C권1호
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• pp.37-50
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• 2009

SCADA(Supervisory Control and Data Acquisition) 시스템은 국가 기반시설에서 주로 사용되는 제어 시스템이다. 과거 SCADA 시스템은 폐쇄 망에서 운영되어진다는 이유로 보안에 대한 고려 없이 설계되었다. 하지만 기술의 발달로 SCADA 시스템과 공용망과의 연계가 추진되면서 보안에 대한 문제점이 대두 되고 있다. 본 논문에서는 SCADA 시스템의 제약사항과 보안요구사항을 살펴보고, 안전한 SCADA 시스템을 위한 키 관리 구조를 제안한다. 기존에 제안되어있는 SCADA 시스템을 위한 키 관리 방식이 메시지 브로드캐스팅을 지원하지 못하는 반면, 제안하는 방식은 메시지 브로드캐스팅을 지원한다. 또한 제안하는 방식은 성능상의 제약을 가지고 있는 RTU의 계산량을 최소화하기 위해, 상위 노드(SUB-MTU 또는 MTU)에 계산량을 분배하여 RTU의 잠재적인 성능 병목을 해결하였다.