• Journal of Applied Biological Chemistry
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• 제55권1호
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• pp.67-70
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• 2012

Plant MYB transcription factors regulate secondary metabolism, cellular morphogenesis, and plant hormone signaling pathway. MYB proteins in plants consist of two repeats of 50 amino acid residues, which are referred to as R2R3 and they interact with WD40 or basic helix loop helix (bHLH) proteins. Yeast two hybrid assay was determined whether rice MYB protein interacts with either OsTTG1, which contains a WD40 domain, or with OsGL3, which contains a bHLH domain. Among 30 OsMYB proteins, three interacted with OsTTG1 and five interacted with OsGL3. A series of MYB mutants were created to determine the MYB domain important for the interaction with OsTTG1 or OsGL3. By using the yeast two hybrid assay, we found that the R3 motif of OsMYB10 and the R2 motif of OsMYB16 were required for interaction with OsTTG1 and OsGL3 proteins, respectively.

• 미생물학회지
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• 제37권1호
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• pp.42-48
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• 2001

출아 효모인 Saccharomyces cerevisiae의 베타-1,3-글루칸 생합성의 결함을 초래하는 돌연변이 유전자(sool-1)를 분리하여 돌연변이 부위의 염기서열을 결정하고 그 특성을 분석하였다. cool-1 유전자의 염기서열 분석 결과, 681번의 염기인 G가 A로 치환되어 Soolp의 $Gly^{227}$이 Asp로 치환되는 결과를 나타내는 것으로 판명되었고, cool-1 유전자는 기존에 보고된 retl-1 유전자와 동일한 돌연변이 유전자로 판명되었다. 그러나, ret1-1이 나타내는 온도감수성 형질은 배지에 1.2 M sorbitol 등의 삼투안정제를 첨가하면 극복될 수 있으며, cool-l/retl-1의 돌연변이 부위가 세포벽합성 관련 단백질의 번역 후 수식과정에 영향을 미친 것임을 확인하였다. 한편, Soolp/$\alpha$-COP의 N-말단에 존재하는 6개의 WD40 domain중 5번째 WD40 domain이 효모의 세포벽 합성이나 구조유지에 중요한 역할을 담당할 것임을 시사하는 결과를 얻었다.

• 생명과학회지
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• 제18권8호
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• pp.1059-1065
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• 2008

KIF21A는 kinesin superfamily에 속하는 분자 motor로서 미세소관을 따라서 분비소포를 운반한다. 최근의 연구결과 KIF21A 유전자 일부의 missense 돌연변이에 의하여 congenital fibrosis of the extraocular muscles (CFEOM) 1의 유발됨이 밝혀졌다. CFEOM1은 KIF21A의 돌연변이로 인하여 분화 발생과정에 occulo-motor신경과 neuromuscular junction 형성에 필요한 단백질을 이동시키지 못함으로써 유발된다. 본 연구에서는 효모 two-hybrid system을 사용하여 KIF21A의 WD-40 repeat domain과 결합하는 분자량이 작은 Purkinje cell protein-1 (Pcp-2), 또는 L7으로도 알려진 단백질을 분리하였다. Pcp-2는 효모 two-hybrid assay에서 KIF21A와 KIF21B의 WD-40 영역과는 결합하지만 다른 종류의 KIFs와는 결합하지 않았다. 또한 단백질간의 특이적 결합을 pull-down assay로 확인하였으며, 생쥐의 뇌 파쇄액에 Pcp-2 항체로 면역침강을 행하여 KIF21A를 확인한 결과 Pcp-2와 같이 침강하였다. 이러한 결과들은 KIF21A는 Pcp-2와 결합하며, 또한 Pcp-2는 KIF21A의 adaptor 단백질로서 세포 내 KIF21A의 수송에서 매개 단백질로 작용함을 시사한다.

• 생명과학회지
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• 제20권8호
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• pp.1166-1172
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• 2010

Kinesin-I은 4분자의 단백질로 구성되어 있으며, N-말단의 motor 영역과 C-말단영역을 가지는 장쇄(KHC, 또한 KIF5s로도 통용) 2분자와 KIF5s (KIF5A, KIF5B와 KIF5C)의 줄기영역과 결합하는 단쇄(KLC) 2분자로 구성되어 있다. KIF5A의 결합 단백질을 동정하기 위하여 효모 two-hybrid system을 사용하여 특이적으로 결합하는 heterotrimeric G 단백질의 ${\beta}$ 단위체 단백질($G{\beta}$)을 분리하였다. $G{\beta}$은 KIF5A의 808에서 935아미노산 부위와 결합하며, 다른 KIF5들과도 결합함을 효모 two-hybrid assay로 확인하였다. 또한 $G{\beta}$의 WD40 반복 서열은 KIF5A와의 결합에 필수영역임을 확인하였으며, 이러한 단백질간의 결합은 Glutathione S-transferase (GST) pull-down assay를 통하여 확인하였다. 생쥐의 뇌 파쇄액에 KIF5들의 항체로 면역침강을 행하여 heterotrimeric G 단백질을 확인한 결과, KIF5들은 heterotrimeric G 단백질과 특이적으로 같이 침강하였다. 이러한 결과들은 kinesin-I는 heterotrimeric G 단백질이 포함된 소포를 미세소관을 따라 이동시킴을 시사한다.

• Molecules and Cells
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• 제22권2호
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• pp.210-219
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• 2006

Dynamin-related protein 2A (AtDRP2A, formally ADL6), a member of the dynamin family, is critical for protein trafficking from the TGN to the central vacuole. However, the mechanism controlling its activity is not well understood in plant cells. We isolated Arabidopsis sec13 homolog1 (AtSeh1) that interacts with AtDRP2A by a yeast two-hybrid screening. AtSeh1 has four WD40 motifs and amino acid sequence homology to Sec13, a component of COPII vesicles. Coimmunoprecipitation and protein pull-down experiments demonstrated specific interaction between AtSeh1 and AtDRP2A. AtSeh1 bound to the pleckstrin homology domain of AtDRP2A in competition with the C-terminal domain of the latter, and this resulted in inhibition of the interaction between AtDRP2A and PtdIns3P in vitro. AtSeh1 localized to multiple locations: the nucleus, the prevacuolar compartment and the Golgi complex. Based on these results we propose that AtSeh1 plays a role in regulating cycling of AtDRP2A between membrane-bound and soluble forms.

• 한국균학회지
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• 제40권4호
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• pp.224-228
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• 2012

A. nidulans ${\alpha}$-COP과 상호작용하는 단백질을 동정하기 위하여 ${\alpha}$-COP을 암호하는 유전자를 bait로 yeast two-hybrid 스크리닝용 A. nidulans cDNA 라이브러리를 탐색한 결과, COPI 소낭의 구성요소 중 하나인 ${\varepsilon}$-COP을 암호화하고 있는 유전자를 동정하고 $aneA^+$($\underline{A}$spergillus $\underline{n}$idulans $\underline{e}$psilon-COP, $AN{\varepsilon}$-COP)으로 명명하였다. $aneA^+$ 유전자는 총 296개의 아미노산을 암호화하고 있으며, 다른 균류의 ${\varepsilon}$-COP과 높은 상동성을 보였다. Yeast two hybrid 시스템으로 두 단백질 간의 상호작용 부위를 분석한 결과, ${\alpha}$-COP의 COOH 도메인과 ${\varepsilon}$-COP의 C-말단부가 필수 부위였으며, ${\alpha}$-COP N-말단의 WD 도메인과 ${\varepsilon}$-COP의 TPR 부위는 두 단백질 간의 결합을 촉진하는 조절부위로 밝혀졌다. 또한 사상균인 A. nidulans와 효모류인 S. cerevisiae에서 ${\alpha}$-COP과 ${\varepsilon}$-COP 간 작용양상이 유사한 것으로 보아, COPI 소낭의 구성요소인 ${\alpha}$-COP과 ${\varepsilon}$-COP 간의 상호작용 기전은 진핵세포 내에서 진화적으로 잘 보존되어 있는 것으로 추정되었다.

• BMB Reports
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• 제43권4호
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• pp.233-244
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• 2010

Parkinson's disease (PD) is the second most common neurodegenerative disease, and 5-10% of the PD cases are genetically inherited as familial PD (FPD). LRRK2 (leucine-rich repeat kinase 2) was first reported in 2004 as a gene corresponding to PARK8, an autosomal gene whose dominant mutations cause familial PD. LRRK2 contains both active kinase and GTPase domains as well as protein-protein interaction motifs such as LRR (leucine-rich repeat) and WD40. Most pathogenic LRRK2 mutations are located in either the GTPase or kinase domain, implying important roles for the enzymatic activities in PD pathogenic mechanisms. In comparison to other PD causative genes such as parkin and PINK1, LRRK2 exhibits two important features. One is that LRRK2's mutations (especially the G2019S mutation) were observed in sporadic as well as familial PD patients. Another is that, among the various PD-causing genes, pathological characteristics observed in patients carrying LRRK2 mutations are the most similar to patients with sporadic PD. Because of these two observations, LRRK2 has been intensively investigated for its pathogenic mechanism (s) and as a target gene for PD therapeutics. In this review, the general biochemical and molecular features of LRRK2, the recent results of LRRK2 studies and LRRK2's therapeutic potential as a PD target gene will be discussed.

• Animal cells and systems
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• 제13권1호
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• pp.9-15
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• 2009

Eph receptors and their ephrin ligands have been implicated in a variety of cellular processes such as cellular morphogenesis and motility. Our previous studies demonstrated that Odin, one of the Anks family proteins, functions as a scaffolding protein of the EphA8 signaling pathway leading to modulation of cell migration or axonal outgrowth. Here we show that WDR7 is associated with Odin and that it is possibly implicated in the EphA8 signaling pathway. WD40 repeats present in the COOH-terminal region of WDR7 appear to be crucial for its association with Odin, whereas the binding motif of Odin is located in between ankyrin repeats and PTB domain. Co-immunoprecipitation experiments revealed that association of WDR7 with Odin is enhanced by ephrin ligand treatment, possibly through forming large protein complexes including both EphA8 and ephrin-A5. Consistently, immunofluorescence staining experiments suggested that WDR7 constitute a component of the large protein complexes containing Odin, EphA8 and ephrin-A5. Taken together, our results suggest the WDR7-Odin complexes might be involved in the signaling pathway downstream of the EphA8 receptor.

• Molecules and Cells
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• 제28권6호
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• pp.529-536
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• 2009

Genome sequencing of the pig is being accelerated because of its importance as an evolutionary and biomedical model animal as well as a major livestock animal. However, information on expressed porcine genes is insufficient to allow annotation and use of the genomic information. A series of expressed sequence tags of 5' ends of five full-length enriched cDNA libraries (SUSFLECKs) were functionally characterized. SUSFLECKs were constructed from porcine abdominal fat, induced fat cells, loin muscle, liver, and pituitary gland, and were composed of non-normalized and normalized libraries. A total of 55,658 ESTs that were sequenced once from the 5′ ends of clones were produced and assembled into 17,684 unique sequences with 7,736 contigs and 9,948 singletons. In Gene Ontology analysis, two significant biological process leaf nodes were found: gluconeogenesis and translation elongation. In functional domain analysis based on the Pfam database, the beta transducin repeat domain of WD40 protein was the most frequently occurring domain. Twelve genes, including SLC25A6, EEF1G, EEF1A1, COX1, ACTA1, SLA, and ANXA2, were significantly more abundant in fat tissues than in loin muscle, liver, and pituitary gland in the SUSFLECKs. These characteristics of SUSFLECKs determined by EST analysis can provide important insight to discover the functional pathways in gene networks and to expand our understanding of energy metabolism in the pig.

• Journal of Photoscience
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• 제12권1호
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• pp.1-9
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• 2005

The ubiquitin E3 ligase COP1 (Constitutive Photomorphogenesis 1) is a protein repressor of photomorphogenesis in Arabidopsisplants, and it found in various organisms, including animals. The COP1 protein regulates the stability of many of the light-signaling components that are involved in photomorphogenesis and in the developmental processes. To study the effect of COP1 on flowering in a short day plant, we have cloned a full-length of PnCOP1 (Pharbitis nil COP1) cDNA from Pharbitis nil Choisy cv. Violet, and we examined its transcript levels under various conditions. A full-length PnCOP1 cDNA consists of 2,280 bp nucleotidesthat contain 47 bp of 5'-UTR, 232 bp of 3'-UTR including the poly (A) tail, and 1,998 bp of the coding sequence. The deduced amino acid sequence contains 666 amino acids, giving it a theoretical molecular weight of 75 kD and a isolectric point of 6.2. The PnCOP1 contains three distinct domains, an N-terminal $Zn^2+$-binding RING-finger domain, a coiled-coil structure, and WD40 repeats at the C-terminal, implying that the protein plays a role in protein-protein interactions. The PnCOP1 transcript was detected in the cotyledon, hypocotyls and leaves, but not in root. The levels of the PnCOP1 transcript were reduced in leaves that were a farther distance away from the cotyledons. The expression level of the PnCOP1 gene was inhibited by light, while the expression was increased in the dark. During the floral inductive 16 hour-dark period for Pharbitis nil, the expression was increased and it reached its maximum at the 12th hour of the dark period. The levels of PnCOP1 mRNA were dramatically reduced upon light illumination. These results suggest that PnCOP1 may play an important function in the floral induction of Pharbitis nil.