• Parasites, Hosts and Diseases
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• 제44권4호
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• pp.331-341
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• 2006

Actin binding proteins play key roles in cell structure and movement particularly as regulators of the assembly, stability and localization of actin filaments in the cytoplasm. In the present study, a cDNA clone encoding an actin bundling protein named as AhABP was isolated from Acanthamoeba healyi, a causative agent of granulomatous amebic encephalitis. This clone exhibited high similarity with genes of Physarum polycephalum and Dictyostelium discoideum, which encode actin bundling proteins. Domain search analysis revealed the presence of essential conserved regions, i.e., an active actin binding site and 2 putative calcium binding EF-hands. Transfected amoeba cells demonstrated that AhABP is primarily localized in phagocytic cups, peripheral edges, pseudopods, and in cortical cytoplasm where actins are most abundant. Moreover, AhABP after the deletion of essential regions formed ellipsoidal inclusions within transfected cells. High-speed co-sedimentation assays revealed that AhABP directly interacted with actin in the presence of up to $10{\mu}M$ of calcium. Under the electron microscope, thick parallel bundles were formed by full length AhABP, in contrast to the thin actin bundles formed by constructs with deletion sites. In the light of these results, we conclude that AhABP is a novel actin bundling protein that is importantly associated with actin filaments in the cytoplasm.

• International Journal of Oral Biology
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• 제30권1호
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• pp.17-22
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• 2005

In the previous studies of Saccharomyces cerevisiae, Abp140p (actin binding protein 140) fused to GFP has been only a protein that can label actin cables of yeast cells so far. However, the role of Abp140p in actin dynamics was remained elusive. In this study, the function of Abp140p was investigated with a deletion mutant and overexpression of GFP fused Abp140p. The deletion mutant was slightly more susceptible to Latrunculin-A (Lat-A), an actin-monomer sequestering agent, than wild type, although no significant deformation of actin structures was caused by ABP 140 deletion. Overexpression of Abp140p-GFP retarded cell growth, and produced thick and robust actin cables. Lat-A was not able to destabilize the thick actin cables, which suggests that actin dynamics was compromised in the cells with surplus of Abp140p. Therefore, Abp140p seems to stabilize actin cables together with other bundling proteins. Recently, actin cable dynamics of budding yeast was found to have a resemblance to that of filopodial tip of cultured mammalian cells. Retrograde movement of actin cables from buds to mother cells indicated local generation of the cable at bud sites. By using Abp140p-GFP, we traced the steps in the generation of a new actin cable after elimination of old cables by sodium azide. Before the appearance of a new actin cable, Abp140p-GFP concentrated in buds and disappeared, as mother cells became abundant in actin cables. Our observations provide a direct evidence of actin cable formation at buds of budding cells.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7221-7227
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• 2013

Background: Fascin, an actin-bundling protein forming actin bundles including filopodia and stress fibers, is overexpressed in multiple human epithelial cancers including esophageal squamous cell carcinoma (ESCC). Previously we conducted a microarray experiment to analyze fascin knockdown by RNAi in ESCC. Method: In this study, the differentially expressed genes from mRNA expression profilomg of fascin knockdown were analyzed by multiple bioinformatics methods for a comprehensive understanding of the role of fascin. Results: Gene Ontology enrichment found terms associated with cytoskeleton organization, including cell adhesion, actin filament binding and actin cytoskeleton, which might be related to fascin function. Except GO categories, the differentially expressed genes were annotated by 45 functional categories from the Functional Annotation Chart of DAVID. Subpathway analysis showed thirty-nine pathways were disturbed by the differentially expressed genes, providing more detailed information than traditional pathway enrichment analysis. Two subpathways derivated from regulation of the actin cytoskeleton were shown. Promoter analysis results indicated distinguishing sequence patterns and transcription factors in response to the co-expression of downregulated or upregulated differentially expressed genes. MNB1A, c-ETS, GATA2 and Prrx2 potentially regulate the transcription of the downregulated gene set, while Arnt-Ahr, ZNF42, Ubx and TCF11-MafG might co-regulate the upregulated genes. Conclusions: This multiple bioinformatic analysis helps provide a comprehensive understanding of the roles of fascin after its knockdown in ESCC.

• Asian Pacific Journal of Cancer Prevention
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• 제16권13호
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• pp.5445-5451
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• 2015

Fascin-1 (FSCN1) is an actin-bundling protein that induces cell membrane protrusions, increases cell motility, and is overexpressed in various human epithelial cancers, including esophageal squamous cell carcinoma (ESCC). We analyzed various protein-protein interactions (PPI) of differentially-expressed genes (DEGs), in fascin knockdown ESCC cells, to explore the role of fascin overexpression. The node-degree distributions indicated these PPI sub-networks to be characterized as scale-free. Subcellular localization analysis revealed DEGs to interact with other proteins directly or indirectly, distributed in multiple layers of extracellular membrane-cytoskeleton/ cytoplasm-nucleus. The functional annotation map revealed hundreds of significant gene ontology (GO) terms, especially those associated with cytoskeleton organization of FSCN1. The Random Walk with Restart algorithm was applied to identify the prioritizations of these DEGs when considering their relationship with FSCN1. These analyses based on PPI network have greatly expanded our comprehension of the mRNA expression profile following fascin knockdown to future examine the roles and mechanisms of fascin action.

• Journal of Chest Surgery
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• 제41권1호
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• pp.74-81
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• 2008

배경: Fascin은 actin-bundling protein으로 세포막 돌출(cell membrane protrusion)을 야기하고 상피세포의 운동성(motility)을 증가시킨다고 알려져 있다. 식도암은 근치적인 수술 후에도 조기에 광범위한 국소침윤이나 국소 임파절의 전이를 자주 일으키는 치명적인 암의 하나이다. 본 연구의 목적은 식도암에 있어서 fascin에 대한 연구가 국내에서는 거의 없는 상황에서 면역조직화학 염색 방법을 이용하여 fascin의 발현 양상을 알아보고 발현여부에 따른 임상 및 병리학적 특성과 예후인자로서의 의의 등을 알아보고자 하였다. 대상 및 방법: 식도 편평 상피암으로 진단받고 수술을 시행 받은 76명의 한자의 암조직에서 fascin의 발현여부를 면역조직화학염색을 통해 조사하였다. Fascin에 대한 면역조직화학 염색에 대한 판독은 반정량적으로 2등급으로 나누었다. 발현양상에 따른 임상 및 병리학적 특성 및 예후분석을 시행하였다. 결과: 전체 76개의 암조직중 39예(51.3%)에서 Fascin의 발현이 양성이었다. Fascia의 발현은 임상병기가 진행될수록(p=0.030), T 인자가 높을수록(p=0.031) 양성률이 높게 나타났으며 추적기간 중 재발이 있었던 군(p=0.005)과 사망을 한 군(p=0.000)에서 양성 발현율이 통계적으로 유의하게 높았다. 각 임상병리학적 인자들의 예후인자로서 단변량 분석 결과 임파절의 전이유무, 림프판 혈관 침범(lymphovascular invasion)여부, 신경주위침범(perineural invasion)여부, 병기, fascin 발현 여부가 통계적으로 유의한 인자들로 나타났다. 다변량 분석에서는 림프관 혈관 침범(lymphovascula. invasion)여부, fascin 발현 여부가 예후인자로 유의하였다. 결론: Fascin은 식도암조직의 51.3%에서 발현되었으며 이의 양성 발현은 보다 진행된 종양 및 재발과 연관성이 있었다. Fascin의 음성발현군이 양성발현군에 비해 유의하게 예후가 좋았으며 Fascin의 발현 여부가 식도암의 예후 인자로서 유용할 수 있음을 알 수 있었다.

• Tuberculosis and Respiratory Diseases
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• 제65권2호
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• pp.105-109
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• 2008

연구배경: Fascin은 세포 운동에 관여하는 액틴 결합 단백질로서 정상적인 상피세포에는 증가되어 있지 않으며, 일부 악성종양에서 fascin이 증가되어 있다는 보고가 있다. 본 연구는 비소세포폐암 환자의 조직에서 fascin 발현을 조사하고 fascin이 예후 인자로 역할을 하는지를 알아보고자 하였다. 방 법: 제 1기 비소세포폐암으로 근치적 절제수술을 받고 추적조사가 가능했던 환자 81명의 조직에서 fascin 발현을 면역조직화학 염색 방법으로 조사하였다. 결 과: Fasin 발현은 전체 81예 중 59예(73%)에서 양성이었다. Fascin 발현 정도에 따른 5년 생존율은 fascin 발현 음성군에서 68%, fascin 저발현군에서 76%, fascin고발현군에서 79%으로 각 군간에 유의한 차이가 없었다(p=0.86). 결 론: Fascin발현이 비소세포폐암으로 근치적 수술을 받은 환자에서 예후 인자로서 역할을 하는지 알아보았으나 통계학적으로 유의한 관련성이 없었다.