• Restorative Dentistry and Endodontics
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• 제32권5호
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• pp.459-468
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• 2007

이 연구에서는 법랑모세포 분화과정에서 APin의 기능을 알아보고자 APin-protein microarray를 시행한 후 치아발생과 관련이 있는 MEF2, Aurora kinase A, BMPR-IB와 EF-hand calcium binding protein을 분석하여 다음과 같은 결과를 얻었다. 1 CMV-APin construct를 transfection하여 APin의 과발현을 유도한 경우에는 MEF2와 Aurora kinase A 둘 모두에서 발현이 현저히 감소한 반면에, APin의 발현억제를 유도한 경우에는 둘 모두 변화가 없었다. 2. APin의 과발현을 유도한 경우에는 BMPR-IB와 EF-hand calcium binding protein 모두에서 발현이 크게 증가한 반면, APin을 발현억제 시킨 경우에는 BMPR-IB는 변화가 없었고, EF-hand calcium binding protein은 현저히 감소하였다. 위의 결과들로 보아 APin 단백질은 MEF2, Aurora kinase A, BMPR-IB, EF-hand calcium binding protein과 상호작용하여 법랑모세포의 분화와 석회화 과정 중에 중요한 역할을 하는 것으로 사료된다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.43-43
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• 2001

In cells of the eukaryotic microorganism Dictyostelium discoideum, at least eight small, four-EF hand calcium-binding proteins respectively are expressed at specific stages during development. One of these proteins, calcium-binding protein 3 (CBP3), first appears just prior to cell aggregation and then maintains relatively constant levels throughout development.(omitted)

• 생명과학회지
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• 제4권2호
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• pp.50-59
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• 1994

신호전달과정의 연구는 calcium이 messenger로서 작용한다고 밝혀진 후로 식물에서 $Ca^{++}$ -messenger system에 대한 생화학적 및 분자생물학적 분야에서의 연구는 급속하게 발전하게 되었다. 식물세포에서 calcium 이온들의 많은 작용은 EF hand family로서 알려진 calcium binding protein에 의해서 조절된다. Calmodulin (CaM)은 highy conserve 되어 있으며, 4개의 calcium binding domain을 가진 ubiquitous한 단백질이다. 본 연구는 calmodulin 유전자의 발현에 미치는 calcium, EGTA, calcium ionophore 및 calmodulin antagonist의 영향과 또한 외부신호(light, wounding), chemical 및 auxin 등의 영향을 reporter화 유전자의 분석에 의해서 CaM유전자의 발현기작을 규명하고자 하였고, 또한 calmodulin 유전자의 organ-specific 발현 및 calmodulin의 새로운 생리적인 기능도 연구하고자 하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제24권3호
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• pp.277-286
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• 2020

Polycystic kidney disease 2-like-1 (PKD2L1), also known as polycystin-L or TRPP3, is a non-selective cation channel that regulates intracellular calcium concentration. Calmodulin (CaM) is a calcium binding protein, consisting of N-lobe and C-lobe with two calcium binding EF-hands in each lobe. In previous study, we confirmed that CaM is associated with desensitization of PKD2L1 and that CaM N-lobe and PKD2L1 EF-hand specifically are involved. However, the CaM-binding domain (CaMBD) and its inhibitory mechanism of PKD2L1 have not been identified. In order to identify CaM-binding anchor residue of PKD2L1, single mutants of putative CaMBD and EF-hand deletion mutants were generated. The current changes of the mutants were recorded with whole-cell patch clamp. The calmidazolium (CMZ), a calmodulin inhibitor, was used under different concentrations of intracellular. Among the mutants that showed similar or higher basal currents with that of the PKD2L1 wild type, L593A showed little change in current induced by CMZ. Co-expression of L593A with CaM attenuated the inhibitory effect of PKD2L1 by CaM. In the previous study it was inferred that CaM C-lobe inhibits channels by binding to PKD2L1 at 16 nM calcium concentration and CaM N-lobe at 100 nM. Based on the results at 16 nM calcium concentration condition, this study suggests that CaM C-lobe binds to Leu-593, which can be a CaM C-lobe anchor residue, to regulate channel activity. Taken together, our results provide a model for the regulation of PKD2L1 channel activity by CaM.

• 통합자연과학논문집
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• 제17권1호
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• pp.31-41
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• 2024

Calcium ions play an important role in development and intracellular signaling. Dictyostelium discoideum has 14 genes encoding calcium -binding proteins (CBPs), but the function of most CBPs during development has not yet been studied. In this study, we investigated the specific functions of CBP7, one of 14 CBPs, in development using RNA interference cell lines of CBP7, cell lines overexpressing CBP7, cell lines with point mutations in the EF-hand domain, and cell lines expressing fragment proteins. was intended to reveal. CBP7 consists of 169 amino acids and contains 4EF-hand domains. The CBP7-overexpressing cells showed complete loss of developmental process. These cells remained in the single-cell growth stage under development -inducing conditions, while wild-type cells formed aggregations within 6-8h of development and eventually formed fruiting bodies. The experiments using point-mutated CBP7 protein showed that all EF-hand domains of CBP7 were important for CBP7 to function during developmental process. These results suggest that CBP7 plays an important role in developmental processes across all EF-hand domains.

• Archives of Pharmacal Research
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• 제23권6호
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• pp.633-636
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• 2000

Translationally controlled tumor protein (TCTP), also known as IgE-dependent histamine-releasing factor, is a growth-related tumor protein. Although the primary sequence of rat TCTP does not reveal any recognizable $Ca^{2+}$ -binding motif, previous studies have demonstrated that rat TCTP consisting of 172 amino acids is a $Ca^{2+}$ -binding protein. However. the region of TCTP required for $Ca^{2+}$ interaction has not been mapped to the molecule. Here, we reported that the $Ca^{2+}$ binding region of TCTP which was mapped by using a combination of deletion constructs of rat TCTP and $^{45}Ca^{2+}$-overlay assay. was confined to amino acid residues 81-112. This binding domain did not show any peculiar loop of calcium- binding motif such as CaLB domain and EF hand motif and it seems to be constituted of random coil regions neighboring the a helix. Thus, our data confirm that TCTP is a novel family of $Ca^{2+}$ -binding protein.

• Journal of Plant Biology
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• 제39권3호
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• pp.173-177
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• 1996

A novel calcium binding protein (CaBP) was purified to electrophoretic homogeneity from Dunaliella salina. In the course of purification experiment, this CaBP was identified as a monomer and its molecular weight was about 21 kDand isoelectric point (pI) value was about 4.1 using isoelectrofocusing. This CaBP was able to bind Ca2+ even in the pressence of an excess MgCl2 and KCI both in solution. In the SDS-PAGE, the Ca2+-bound form was slower than the Ca2+-free form in the nondenaturing PAGE. This means that the CaBP undergoes conformational change in the Ca2+-bound condition. Furthermore, UV absorption spectrum and fluorescence intensity of this CaBP was investigated. UV absorption peak was appeared at about 258 nm and decreased somewhat in Ca2+-bound condition. In the measurement of fluorescence, maximum intensity was appeared at 303 nm and decreased in Ca2+-bound state, similarly as UV absorption spectrum. These show distinct changes upon Ca2+-binding, which indicate of structural and/or dynamic changes largely reminiscent of other members of the EF-hand Ca2+-binding protein family.

• Parasites, Hosts and Diseases
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• 제48권4호
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• pp.319-324
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• 2010

A family of calcium-dependent protein kinases (CDPKs) is a unique enzyme which plays crucial roles in intracellular calcium signaling in plants, algae, and protozoa. CDPKs of malaria parasites are known to be key regulators for stage-specific cellular responses to calcium, a widespread secondary messenger that controls the progression of the parasite. In our study, we identified a gene encoding Plasmodium vivax CDPK4 (PvCDPK4) and characterized its molecular property and cellular localization. PvCDPK4 was a typical CDPK which had well-conserved N-terminal kinase domain and C-terminal calmodulin-like structure with 4-EF hand motifs for calcium-binding. The recombinant protein of EF hand domain of PvCDPK4 was expressed in Echerichia coli and a 34 kDa product was obtained. Immunofluorescence assay by confocal laser microscopy revealed that the protein was expressed at the mature schizont of P. vivax. The expression of PvCDPK4-EF in schizont suggests that it may participate in the proliferation or egress process in the life cycle of this parasite.

• 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.

• Journal of Plant Biotechnology
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• 제2권2호
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• pp.97-99
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• 2000

Allergy to Brassica pollen has been reported in some countries. We have cloned a cDNA encoding a Brassica pollen allergen, Bra r 1. Bra r 1 belongs to a new family of $Ca^{2+}$-binding proteins, characterized by the presence of two EF-hand calcium-binding domains. Bra r 1 was detected in the tapetum, microspores, pollen coat and pollen tubes, indicating Bra r 1 is involved in pollen pistil interaction and pollen tube growth. We have engineered the hypoallergenic mutants of Bra r 1 for immunotherapy. Here we describe the review of molecular characterization of Bra r 1.