• 대한수의학회지
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• 제39권1호
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• pp.34-44
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• 1999

Ischemic damage in the selectively vulnerable populations of neurons is thought to be caused by an abnormal accumulation of intracellular calcium. It has been reported that the neurons, expressing specific calcium binding proteins, might effectively control intracellular calcium concentrations because of a high capacity to buffer intracellular calcium in the brain ischemic condition. It is uncertain that parvalbumin, one of the calcium binding proteins, can protect the neurons from the cerebral ischemic damage. Recently, treatment of kappa opioid agonists increased survival rate, improved neurological function, and decreased tissue damage under the cerebral ischemic condition. Many evidences indicate that these therapeutic effects might result from regulation of calcium concentration. This study was designed to analyze the changes of number in parvalbumin-positive neurons after cerebral ischemic damage according to timepoints after cerebral ischemic induction. In addition, we evaluated the effect of GR89696 (kappa opioid agonist) or naltrexone(non selective opioid antagonist) on the changes of number in parvalbumin expressing neurons under ischemic condition. Cerebral ischemia was induced by occluding the common carotid artery of experimental animals. The hippocampal areas were morphometrically analyzed at different time point after ischemic induction(1, 3, 5 days) by using immuno-histochemical technique and imaging analysis system. The number of parvalbumin-positive neurons in hippocampus was significantly reduced at 1 day after ischemia(p<0.05). Furthermore, the number of parvalbumin-immunoreactive neurons was dramatically reduced at 3 and 5 days after cerebral ischemic induction(p<0.05) as compared to 1 day group after ischemia, as well as sham control group. Significant reduction of parvalbumin positive neurons in CA1 region of hippocampus was observed at 1 day after cerebral ischemic induction. However, significant loss of MAP2 immunoreactivity was observed at 3 day after cerebral ischemia. The loss of parvalbumin-positive neurons and MAP2 immunoreactivity in CA1 region was prevented by pre-administration of GR89696 compared to that of saline-treated ischemic group. Furthermore, protective effect of GR89696 partially reversed by pre-treatment of naltrexone. These data indicate that parvalbumin-positive neurons more sensitively responded to cerebral ischemic damage than MAP2 protein. Moreover, this loss of parvalbumin-positive neurons was effectively prevented by the pretreatment of kappa opioid agonist. It was also suggested that the changes of number in parvalbumin-positive neurons could be used as the specific marker to analyze the degree of ischemic neuronal damage.

• 생명과학회지
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• 제19권1호
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• pp.129-137
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• 2009

$Ca^{2+}$은 다양한 자극과 빛, biotic, abiotic 스트레스, 호르몬 등의 반응에 대한 세포내 2차 신호전달물질로써 중요한 역할을 한다. $Ca^{2+}$의 반응자들은 특정 물질과 경로를 활성화함으로써 신호전달 기능을 한다고 알려져 있는 $Ca^{2+}$ 결합 단백질들이다. 이들 단백질 중, calmidulin (CaM)은 식물과 동물의 특정 단백질의 활성을 조절하는 것으로 잘 알려져 왔다. 특히, 식물은 다양한 CaM 유전자와 특징적인 protein kinase와 전사인자를 포함한 많은 종류의 CaM 관련 단백질들을 가지고 있다. 이로 인해서 식물은 주변의 여러 가지 신호등을 인지할 수 있을 뿐만 아니라 변화된 환경에 적응할 수 있는 것이다. 하지만, 대부분의 CaM이나 이들과 관련된 단백질들의 기능은 최근 활발히 연구되고 있지만 아직 많은 작용 기작이 연구의 대상이 되고 있다. 따라서 CaM의 기능을 좀 더 이해한다면 식물의 환경적 자극에 대한 반응과 식물의 성장과 발달에 있어서 CaM의 역할을 규명하는데 도움을 줄 수 있을 것으로 기대된다. 본 논문은 $Ca^{2+}$-CaM의 신호전달 시스템과, CaM과 관련된 단백질들, 그리고 식물의 biotic, abiotic 스트레스에 대한 외부 자극의 반응에 있어서 CaM의 작용에 대해 기술하였다.

• BMB Reports
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• 제41권11호
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• pp.771-777
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• 2008

Calmodulin (CaM) proteins, members of the EF-hand family of $Ca^{2+}$-binding proteins, represent important relays in plant calcium signals. Here, OsCam1-1 was isolated by PCR amplification from the rice genome. The gene contains an ORF of 450 base pairs with a single intron at the same position found in other plant Cam genes. A promoter region with a TATA box at position-26 was predicted and fused to a gus reporter gene, and this construct was used to produce transgenic rice by Agrobacterium-mediated transformation. GUS activity was observed in all organs examined and throughout tissues in cross-sections, but activity was strongest in the vascular bundles of leaves and the vascular cylinders of roots. To examine the properties of OsCaM1-1, the encoding cDNA was expressed in Escherichia coli. The electrophoretic mobility shift when incubated with $Ca^{2+}$ indicates that recombinant OsCaM1-1 is a functional $Ca^{2+}$-binding protein. In addition, OsCaM1-1 bound the CaMKII target peptide confirming its likely functionality as a calmodulin.

• BMB Reports
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• 제56권3호
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• pp.172-177
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• 2023

BEST family is a class of Ca²⁺-activated Cl- channels evolutionary well conserved from bacteria to human. The human BEST paralogs (BEST1-BEST4) share significant amino acid sequence homology in the N-terminal region, which forms the transmembrane helicases and contains the direct calcium-binding site, Ca²⁺-clasp. But the cytosolic C-terminal region is less conserved in the paralogs. Interestingly, this domain-specific sequence conservation is also found in the BEST1 orthologs. However, the functional role of the C-terminal region in the BEST channels is still poorly understood. Thus, we aimed to understand the functional role of the C-terminal region in the human and mouse BEST1 channels by using electrophysiological recordings. We found that the calcium-dependent activation of BEST1 channels can be modulated by the C-terminal region. The C-terminal deletion hBEST1 reduced the Ca²⁺-dependent current activation and the hBEST1-mBEST1 chimera showed a significantly reduced calcium sensitivity to hBEST1 in the HEK293 cells. And the C-terminal domain could regulate cellular expression and plasma membrane targeting of BEST1 channels. Our results can provide a basis for understanding the C-terminal roles in the structure-function of BEST family proteins.

• BMB Reports
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• 제33권4호
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• pp.289-293
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• 2000

Annexin I is a 37 kDa member of the annexin family of calcium-dependent phospholipid binding proteins. Annexin I plays regulatory roles in various cellular processes including cell proliferation and differentiation. Recently we found that annexin I is a heat shock protein (HSP) and displays a chaperone-like function. In this paper we investigated the function of annexin I as an ATPase using 1 to 32 amino acids deleted annexin I (${\Delta}-annexin$ I). ${\Delta}-Annexin$ I hydrolyzed ATP as determined by thin layer chromatography. The ability of ATP hydrolysis was inhibited by ADP, GTP and GDP, but not by the AMP, GMP and cAMP. In view of the ATP hydrolyzing function of HSP, the results support the function of annexin I as a HSP.

• 한국수정란이식학회지
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• 제24권4호
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• pp.237-247
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• 2009

Melatonin (N-acetyl-5-methoxytryptamine) is the major neurohormone secreted during the night by the vertebrate pineal gland. The circadian pattern of pineal melatonin secretion is related to the biological clock within the suprachiasmatic nucleus (SCN) of the hypothalamus in mammals. The SCN coordinates the body's rhythms to the environmental light-dark cycle in response to light perceived by the retina, which acts mainly on retinal ganglion cells that contain the photopigment melanopsin. Calbindin-D9k (CaBP-9k) is a member of the S100 family of intracellular calcium- binding proteins, and in this review, we discuss the involvement of melatonin and CaBP-9k with respect to calcium homeostasis and apoptotic cell death. In future studies, we hope to provide important information on the roles played by CaBP-9k in cell signal transduction, cell proliferation, and $Ca^{2+}$ homeostasis in vivo and in vitro.

• 대한의생명과학회지
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• 제26권1호
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• pp.1-7
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• 2020

Alzheimer's disease (AD) is the most common neurodegenerative disorder and is expected to become more and more widespread as life expectancy increases. New therapeutic target, as well as the identification of mechanisms responsible for pathology, is urgently needed. Recently, microglial actin cytoskeleton has been proposed as a beneficial role in axon regeneration of brain injury. This review highlights in understanding of the characteristics of microglial actin cytoskeleton and discuss the role of specific actin-interacting proteins and receptors in AD. The precise mechanisms and functional aspects of motility by microglia require further study, and the regulation of microglial actin cytoskeleton might be a potential therapeutic strategy for neurological diseases.

• 생명과학회지
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• 제17권12호
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• pp.1649-1653
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• 2007

무더운 날씨가 지속됨으로서 고랭지배추의 생장 및 결구가 지연되고 있는 강원도 정선군 질운산(새빗재)의 600 m와 900 m의 배추를 사용하여 무기성분 및 단백질 발현패턴을 분석하였다. 식물체 무기성분에서는 생장에 관련된 질소 및 인산의 부족현상과 결구에 관련된 칼슘이 부족하였다. 단백체 분석은 2차원 전기영동에 의해 전체 126개의 단백질이 분리되었고 그중 48개의 단백질이 고도에 따라 변화하는 양상을 보여주었다. 이 중에서 30개의 단백질 서열이 결정되었는데, 해발 900 m에서 단백질 발현이 증가한 14개 중에서 oxygen- evolving proteins, rubisco activase and ATPase 등이, 해발 600 m에서는 glutathione S-transferase (1, 28 kD cold induced- and 24kD auxin-binding proteins) and salt-stress induced protein 등 16개의 단백질 발현이 증가하였다. 이러한 단백질은 식물체 손상에 대한 보호기작을 가진 스트레스관련 단백질로 가뭄, 온도상승, 밤낮의 온도차 등의 반복으로 복합적이며 동시 다발적으로 나타나는 고온장해 현상으로 사료된다.

• 생명과학회지
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• 제17권9호통권89호
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• pp.1177-1181
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• 2007

칼모둘린은 칼슘과 결합하는 센서로써 다양한 칼모둘린 결합 단백질들과의 상호 작용을 통하여 세포 내에서 여러가지 기능을 조절한다. 진핵 생물들은 많은 종류의 칼모둘린 결합 단백질을 가지고 있기 때문에 이러한 단백질들의 분리와 특성 규명이 중요하다. 이미 여러 가지 방법들을 이용하여 칼모둘린 결합 단백질들이 분리되었고 이미 알려진 단백질의 구조적인 유사성을 토대로 더 많은 단백질들이 예측되었다. 우리는 애기장대에서 칼모둘린 결합 단백질의 분리와 특성 규명을 위해 형광 단백질과 융합된 칼모둘린 과발현 형질 전환체를 제조하여 공촛점 현미경과 Western blot 을 이용하여 과발현 형질 전환체를 선별하였다. 또한 형질 전환체 내의 칼모둘린이 칼모둘린 결합 단백질과 상호 작용함을 pull-down 분석을 통해서 확인하였다. 이러한 결과들을 토대로 칼모둘린 과발현 형질 전환체를 이용하여, 칼모둘린과 상호 작용하는 여러 가지 칼모둘린 결합 단백질들을 분리할 수 있을 것으로 기대된다.

• BMB Reports
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• 제38권4호
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• pp.432-439
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• 2005

$Ca^{2+}$/calmodulin transduction pathways have been implicated in mediating stress response and tolerance in plants. Here, three genes encoding calmodulin (Cam) members of the EF-hand family of $Ca^{2+}$-binding proteins were identified from Oryza sativa L. databases. Complementary DNA for each of the calmodulin genes, OsCam1, OsCam2, and OsCam3 were sequenced. OsCam1 and OsCam2 encode a conventional 148-amino acid calmodulin protein that contains four characteristic $Ca^{2+}$-binding motifs. OsCam3 encode a similar protein with a 38-amino-acid extension containing a putative prenylation site (CVIL) at the carboxyl terminus. RT-PCR showed that each of the genes is expressed in leaves and roots of 2-week old rice seedlings. By RNA gel blot analysis, OsCam1 mRNA levels strongly increased in response to NaCl, mannitol and wounding treatments. In contrast, OsCam2 mRNA levels were relatively unchanged under all conditions investigated. NaCl treatment and wounding also increased the OsCam3 mRNA level, but in a more transient manner. Our results indicate that although the expression of genes encoding different calmodulin isoforms is ubiquitous, they are differentially regulated by various stress signals. In addition, we have demonstrated that the calcium-channel blocker lanthanum chloride inhibited the induction of OsCam1 gene expression by both NaCl and mannitol treatments. These results suggest that osmotic stress induced expression of OsCam1 gene requires the $[Ca^{2+}]_{cyt}$ elevation that is known to occur in response to these stimuli.