• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.23.2-23.2
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• 2007

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• The Plant Pathology Journal
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• 제34권6호
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• pp.470-479
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• 2018

The rice blast pathogen Magnaporthe oryzae is a global threat to rice production. Here we characterized RHO2 gene (MGG_02457) that belongs to the Rho GTPase family, using a deletion mutant. This mutant ${\Delta}Morho2$ exhibited no defects in conidiation and germination but developed only 6% of appressoria in response to a hydrophobic surface when compared to the wild-type progenitor. This result indicates that MoRHO2 plays a role in appressorium development. Furthermore, exogenous cAMP treatment on the mutant led to appressoria that exhibited abnormal morphology on both hydrophobic and hydrophilic surfaces. These outcomes suggested the involvement of MoRHO2 in cAMP-mediated appressorium development. ${\Delta}Morho2$ mutation also delayed the development of appressorium-like structures (ALS) at hyphal tips on hydrophobic surface, which were also abnormally shaped. These results suggested that MoRHO2 is involved in morphological development of appressoria and ALS from conidia and hyphae, respectively. As expected, ${\Delta}Morho2$ mutant was defective in plant penetration, but was still able to cause lesions, albeit at a reduced rate on wounded plants. These results implied that MoRHO2 plays a role in M. oryzae virulence as well.

• BMB Reports
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• 제49권11호
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• pp.623-628
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• 2016

GPR78 is an orphan G-protein coupled receptor (GPCR) that is predominantly expressed in human brain tissues. Currently, the function of GPR78 is unknown. This study revealed that GPR78 was expressed in lung cancer cells and functioned as a novel regulator of lung cancer cell migration and metastasis. We found that knockdown of GPR78 in lung cancer cells suppressed cell migration. Moreover, GPR78 modulated the formation of actin stress fibers in A549 cells, in a RhoA- and Rac1-dependent manner. At the molecular level, GPR78 regulated cell motility through the activation of $G{\alpha}q$-RhoA/Rac1 pathway. We further demonstrated that in vivo, the knockdown of GPR78 inhibited lung cancer cell metastasis. These findings suggest that GPR78 is a novel regulator for lung cancer metastasis and may serve as a potential drug target against metastatic human lung cancer.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.47.2-47.2
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• 2007

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• 생명과학회지
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• 제17권2호통권82호
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• pp.192-197
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• 2007

외부 병원체 침입으로 이동하고 있는 T 세포는 두가지 뚜렷한 형태적인 변화, 즉, leading edge와 uropod를 형성하여 효과적으로 T세포 이동에 영향을 미친다. Uropod 구조물은 이동하는 림프구들의 뒤쪽에서 관찰 할 수 있는 아주 독특한 구조로 CD44, ERM, F-actin과 같은 단백질들이 서로 영향을 미치며 모인다. F-actin cytoskeleton은 세포의 형태를 유지하는 기본적인 틀을 제공한다. Rho A small GTPase는 이러한 cytoskeleton을 재구성하는 organizer로 역할을 한다고 보고되어 왔다. 지금까지, 다양한 경로를 통하여 Rho A가 활성화 되어 진다고 보고 되었다. 본 실험에서 PDZ 도메인이 세포 내부 RHo A에 GDP가 결합된 불활성화 형태의 Rho A를 GTP가 결합된 활성화 형태로 전환한다는 것을 알았고, F-actin cytoskeleton을 재구성 하며, PDZ 도메인을 함유한 세포는 uorpod 구조물이 없어졌으며 세포 이동 속도도 감소하는 것을 알았다. 따라서 Rho A와 F-actin cytoskeleton 사이의 신호 전달 과정이 uropod 형성에 아주 중요한 기능을 할 것이라는 것을 알았다.

• 생명과학회지
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• 제18권7호
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• pp.918-923
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• 2008

안지오텐신II 수용체(AT1 수용체)는 혈관수축과 체내 전해질이온 조절에 중요한 역할을 한다. AT1 수용체 길항제(ARB)는 고혈압 치료에 이용되며 최근에는 당뇨병을 포함한 대사질환에 효능이 있음이 알려져 있다. 이 연구에서는 ARB 처리 후 세포 내 인산화단백질에 인산화가 일어나는지를 antibody array를 이용하여 실험하였다. 아미노산세린 및 트레오닌에 인산화되는 단백질 6개, 티로신에 인산화되는 단백질 12개에 대한 항체를 선정하여 nitrocellulose membrane에 부착시켰다. AT1 수용체를 발현한 COS-1 세포에 로사틴(losartan)을 처리하였을 때 small GTPase인 RhoA의 세린 잔기에 인산화가 20% 증가함을 관찰하였다. RhoA는 세포골격의 재배열에 중요한 역할을 하며 세린 잔기에 인산화가 되면 활성이 억제된다. 본 연구결과로부터 ARB가 AT1 수용체에 의한 혈관수축을 억제할 뿐만 아니라 새로운 세포 신호룰 생성함을 알 수 있다.

• Biomolecules & Therapeutics
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• 제30권1호
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• pp.98-116
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• 2022

The small GTPase RhoA has been studied extensively for its role in actin dynamics. In this study, multiple bioinformatics tools were applied cooperatively to the microarray dataset GSE64714 to explore previously unidentified functions of RhoA. Comparative gene expression analysis revealed 545 differentially expressed genes in RhoA-null cells versus controls. Gene set enrichment analysis (GSEA) was conducted with three gene set collections: (1) the hallmark, (2) the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and (3) the Gene Ontology Biological Process. GSEA results showed that RhoA is related strongly to diverse pathways: cell cycle/growth, DNA repair, metabolism, keratinization, response to fungus, and vesicular transport. These functions were verified by heatmap analysis, KEGG pathway diagramming, and direct acyclic graphing. The use of multiple gene set collections restricted the leakage of information extracted. However, gene sets from individual collections are heterogenous in gene element composition, number, and the contextual meaning embraced in names. Indeed, there was a limit to deriving functions with high accuracy and reliability simply from gene set names. The comparison of multiple gene set collections showed that although the gene sets had similar names, the gene elements were extremely heterogeneous. Thus, the type of collection chosen and the analytical context influence the interpretation of GSEA results. Nonetheless, the analyses of multiple collections made it possible to derive robust and consistent function identifications. This study confirmed several well-described roles of RhoA and revealed less explored functions, suggesting future research directions.

• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2008년도 춘계학술대회
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• pp.84-84
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• 2008

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.171-175
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• 2008

Here, we report that Vibrio parahaemolyticus induces a rapid remodeling of macrophage actin and activates RhoB GTPase. Mutational analysis revealed that the effects depend on type III secretion system 1 regulated translocation of a V. parahaemolyticus effector protein, VP1686, into the macrophages. Remodeling of actin is shown to be necessary for increased bacterial uptake followed by initiation of apoptosis in macrophages. This provides evidence for functional association of the VP1686 in triggering an eat me-and-die signal to the host.

• Molecules and Cells
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• 제44권7호
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• pp.458-467
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• 2021

GPR43 (also known as FFAR2 or FFA2) is a G-protein-coupled receptor primarily expressed in immune cells, enteroendocrine cells and adipocytes that recognizes short-chain fatty acids, such as acetate, propionate, and butyrate, likely to be implicated in innate immunity and host energy homeostasis. Activated GPR43 suppresses the cAMP level and induces Ca²⁺ flux via coupling to Gα_i and Gα_q families, respectively. Additionally, GPR43 is reported to facilitate phosphorylation of ERK through G-protein-dependent pathways and interacts with β-arrestin 2 to inhibit NF-κB signaling. However, other G-protein-dependent and independent signaling pathways involving GPR43 remain to be established. Here, we have demonstrated that GPR43 augments Rho GTPase signaling. Acetate and a synthetic agonist effectively activated RhoA and stabilized YAP/TAZ transcriptional coactivators through interactions of GPR43 with Gα_q/11 and Gα_12/13. Acetate-induced nuclear accumulation of YAP was blocked by a GPR43-specific inverse agonist. The target genes induced by YAP/TAZ were further regulated by GPR43. Moreover, in THP-1-derived M1-like macrophage cells, the Rho-YAP/TAZ pathway was activated by acetate and a synthetic agonist. Our collective findings suggest that GPR43 acts as a mediator of the Rho-YAP/TAZ pathway.