• The Korean Journal of Zoology
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• v.35 no.3
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• pp.277-286
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• 1992

개구리의 난자로 부터 maturation promoting factor(MPF)를 추출, 부분 분리하여 이들의 활성을 조사하고 이 물질의 생성과 protein kinase C(반KC)와의 관계를 조사하SB다. 성숙된 난자를 분쇄한 후 초원심분리과정을 거쳐 MPF의 crude extract(CE)를 얻은 다음 ultrafiltration (UF)과 고속액체크로마토그라피를 거쳐서 3종류의 분획 (peak 1, 11, and 111)을 얻었다. 이들 분획을 in nitro assay와 autoradiDgraphy를 사용하여 확인한 결과 분획 11에서 MPF 활성이 있는 것을 알았다. 분리 단계에 따라 MPF의 정제도를 Hl histone kinase assay로 조사한 결깍 UF를 거친 것은 CE보다 약 3배로, 분획 11에서는 약 117배로 증가한 것을 확인하였다. 또한 MPF분획의 인산화를 autoradiography로 조사한 결과 45 KD 단백질을 포함한 수종의 난자 단백질이 강하게 인산화되었음을 알 수 있었다. PKC의 활성화가 난자내 MPF의 생성을 유도하는가를 보기 위하여 PKC의 활성제인 12-0-tetradecanoyl phorbol 13 acetate(TPA)를 처리한 난자의 세포질 추출물을 미세주입 법으로 조사한 결과 TPA 처리 후 6시간부터 난자내 MPF의 활성이 나타나는 것을 알 수 있었다. 이러한 결과들은 PKC의 활성화가 MPF의 생성을 유도하고, MPF의 활성화와 함께 일부 단백질들의 인산화를 통하여 궁극적으로 난자 성숙을 촉진했음을 시사한다.

• The Korean Journal of Zoology
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• v.35 no.1
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• pp.37-44
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• 1992

북방산개구리, 참개구리 및 옴개구리를 사용하여 성숙된 난자의 세포질에서 활성을 띠는 성숙촉진요인( maturation promoting factor, MPF)을 미세주입 법으로 확인하고 이들의 성질을 조사하였다. 핵붕괴(germinal vesicle breakdown, GVBD)된 난자의 세포질을 미성숙 난자(GV난자)에 주입하고(75-100 nl) 이들을 15-24시간 배양했을 때 대부분의 GV 난자들이 핵붕괴를 일으켰으나(약 80%) 미성숙 난자(GV 난자)의 세포질을 주입했을 때에는 약 200nl의 난자들만이 핵붕괴를 일으켰다. 핵붕괴된 난자들의 crude extract를 주입했을 때에도 역시 성숙유도 효과가 있었으며 이종간에도 효과가 있었다. 난자의 성숙을 잘 일으키지 않는 옴개구리의 난자를 사용하여 MPF를 가진 세포질을 계대주입(serial transfer)하였을 때에도 MPF가 계속 활성을 띠는 것을 확인할 수 있었다. 아울러 개구리 난자의 MPF생성과 증폭과정에 CAMP의 증가나 단백질 합성의 저해가 미치는 영향을 조사한 결과. MPF의 작용이 유의하게 이들에 의해 억제되는 것을 알 수 있었다.

• The Korean Journal of Zoology
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• v.36 no.2
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• pp.277-284
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• 1993

A possible involvement of maturation promoting factor (nfPF) in the two-cell block phenomenon was studied by fusion experiments. Germinal vesicle (GlF) ooeyte was fused with a blastomore from late or blocked 2-cell mouse embryos. and germinal vesicle breakdoum (GVBD) of fused GV oocvtes in the presence of dbcAMP (100$\mu$g/ml) was scored as an index of MPF aniviD. GnD was induced approximately 30% by fusion of a blastomere derived from late 2-cell embryos, but not from blocked 2-cell embryos. The rate of GVBD was changed when GV oocyte was fused with a blastomere from late 2-cell embryos which were treated with u-amanitin, puromvcin or colcemid before and after hsion: Treatment of late 2-cell embryos with puromycin (50 Is/mll but not with u-amanitin (100 Is/ml) clearly inhibited GVBD, indicating that do novo protein synthesis maw be required for the appearance of MPF activity in late 2-cell embryos. Treatment of late 2-cell embryos w기h colcemid (0.1 Is/mll doubled GVBD, presumably due to the maintenance of metaphase or mitotic phase. SDS-PAGE and twoiimensional electrophoresis revealed that there was no difference in protein synthetic pattern in late and blocked 2-cell embryos, but three phosphoproteins with 27, 35 and 46 M)a, presumsblv M-phase components were phosphorylated in late 2-cell embryos but not in blocked 2-cell embryos. It seems then that MPF activity is closely related to phosphorylstion of M-phase components in late 2-cell embryos.

• The Korean Journal of Zoology
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• v.37 no.1
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• pp.58-65
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• 1994

Phosphatase의 저해제로 알려진 okadaic acid(OA)가 한국산 개구리(북방산개구리 참개구리) 난자의 성숙에 미치는 효과를 조사하였다. 북방산개구리 난자에 약 50 nl의 okadaic acid(0 5-500 mM)를 미세주입한 후 18시간 배양한 결과 0.5 mM의 농도에서 부터 난자의 핵붕괴를 일으키기 시작하였다 동면초기에 처리한 progesterone에 반응하지 않는 난자들도 OA에 의하여 성숙을 일으켰으며. 이 성숙은 배양액에 첨가한 cycloheximide(10 mg/ml)에 영향을 받지 않았다 또한 OA의 처리를 받고 일정시간 배양한 난자의 세포질에는 미성숙 난자의 성숙을 유도하는 maturation promoting factor (MPF)의 활성이 생기었다 참개구리의 난자도 역시 OA에 의해 성숙이 유도되었으며, 주입 후 6시간에서부터 핵붕괴가 일어나기 시작하였다 참개구리에서도 OA의 처리가 MPF의 활성을 촉진하는 것을 세포질내에 Hl histone kinase의 활성도가 증가하는 것으로 확인할 수 있었다 참개구리에서도 OA에 의한 성숙은 cycloheximide나 CAMP에 의해 영향을 받지 않았다 이러한 결과들은 개구리 난자의 MPF 활성화와 성숙과정에 phosphatase가 관여함을 보여주는 것이다.

• Journal of Embryo Transfer
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• v.30 no.1
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• pp.33-43
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• 2015

Successful somatic cell nuclear transfer (SCNT) has been reported across a range of species using a range of recipient cells including enucleated metaphase II (MII) arrested oocytes, enucleated activated MII oocytes, and mitotic zygotes. However, the frequency of development to term varies significantly, not only between different cytoplast recipients but also within what is thought to be a homogenous population of cytoplasts. One of the major differences between cytoplasts is the activities of the cell cycle regulated protein kinases, maturation promoting factor (MPF) and mitogen activated protein kinase (MAPK). Dependent upon their activity, exposure of the donor nucleus to these kinases can have both positive and negative effects on subsequent development. Co-ordination of cell cycle stage of the donor nucleus with the activities of MPF and MAPK in the cytoplast is essential to avoid DNA damage and maintain correct ploidy. However, recent information suggests that these kinases may also effect reprogramming of the somatic nucleus and preimplantation embryo development by other mechanisms. This article will summarise the differences between cytoplast recipients, their effects on development and discuss the potential role/s of MPF and or MAPK in nuclear reprogramming.

• Journal of Life Science
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• v.25 no.10
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• pp.1184-1195
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• 2015

The zebrafish is an emerging vertebrate model organism in reproductive biology. The oocyte maturation of zebrafish is triggered by maturation inducing hormone (MIH, 17α,20β-Dihydroxy-4-pregnen-3-one). In almost all animals, the oocyte maturation is governed by activation of pre-MPF which consists of cyclinB and inactive Cdk1. In the oocyte of Xenopus and mice, the activity of Cdk1 is regulated in two ways, one is the interaction with cyclinB and the other is phosphorylation/dephosphorylation of T14/Y15 residues on the Cdk1 by Wee1 and Cdc25. Unlike Xenopus and mice that have a sufficient amount of pre-MPF, pre-MPF is absent in GV oocyte of most teleost including zebrafish. Therefore, the activation of MPF during zebrafish oocyte maturation might totally depend on de novo synthesis of cyclinB proteins. It is reported that the translation of maternal mRNA is regulated by combination of several RNA binding proteins such as CPEB, Dazl, Pum1/Pum2, and insulin-like growth factor2 mRNA-binding protein 3 in the zebrafish oocytes. However, the definitive mechanism of these proteins to regulate the translation of stored maternal mRNAs remains to be elucidated. Therefore, the investigation of the maturation process of the zebrafish oocyte will provide new information that can help identify the role of translational control in early vertebrate oocyte maturation.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.255-255
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• 2004

본 연구는 한우 체세포 복제수정란의 발달에 있어서 난자가 체외성숙 된 시간이 미치는 영향을 확인하고, 또한 체외성숙 시간별 성숙난자의 MPF 활성도 변화를 조사함으로서 소 복제수정란 생산을 위한 적정 체외성숙 조건을 살펴보는데 목적이 있었다. 도축된 한우로부터 채취된 난소로부터 미성숙 난자를 채취하여, 1 ㎍/㎖ FSH와 1 ㎍/㎖ E2가 첨가된 TCM-199 배양액에서 18, 20, 22시간 체외성숙 후에 각각 성숙난자를 회수하여 22시간째 제핵을 실시하였다. (중략)

• Molecules and Cells
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• v.40 no.11
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• pp.871-879
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• 2017

Levels of maturation-promoting factor (MPF) in oocytes decline after vitrification, and this decline has been suggested as one of the main causes of low developmental competence resulting from cryoinjury. Here, we evaluated MPF activity in vitrified mouse eggs following treatment with caffeine, a known stimulator of MPF activity, and/or the proteasome inhibitor MG132. Collected MII oocytes were vitrified and divided into four groups: untreated, 10 mM caffeine (CA), $10{\mu}M$ MG132 (MG), and 10 mM caffeine + $10{\mu}M$ MG132 (CA+MG). After warming, the MPF activity of oocytes and their blastocyst formation and implantation rates in the CA, MG, and CA+MG groups were much higher than those in the untreated group. However, the cell numbers in blastocysts did not differ among groups. Analysis of the effectiveness of caffeine and MG132 for improving somatic cell nuclear transfer (SCNT) technology using cryopreserved eggs showed that supplementation did not improve the blastocyst formation rate of cloned mouse eggs. These results suggest that maintaining MPF activity after cryopreservation may have a positive effect on further embryonic development, but is unable to fully overcome cryoinjury. Thus, intrinsic factors governing the developmental potential that diminish during oocyte cryopreservation should be explored.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.258-258
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• 1994

본 연구에서는 토양균이 생성하는 2차 대사산물로부터 세포증식 촉진인자 (Maturation Promoting Factor. MPF)인 cdc2/cdk2-cyclin의 복합체를 특이적으로 억제하는 물질을 분리하고 그 물질의 생리활성을 조사하였다. 토양으로부터 순수분리된 300여개의 토양균에서 생성된 배양액을 취하여 MPF의 특이적인 기질인 합성 peptide (CSH103 :HATPPKKKRK)를 사용하여 인산화 활성을 측정하였다. 그중 MPF 활성 억제능이 90％ 이상인 19개의 균주를 1차적으로 선정한 후 각각에 대하여 열/pH에 대한 안정성, 각종 용매에 대한 추출성 등 이화학적 성질을 규명하였으며 이중 균주 LPL 931로부터 MPF 활성 억제제를 분리하고자 하였다. 예비실험의 결과로부터 토양균 LPL 931을 대량배양하여 열처리하고, 비이온성 수지인Amberlite XAD-2에 결합시키고 70% acetone으로 용출시켰다. 이 추출물로부터 ethylacetate와 n-butanol을 사용하여 MPF 억제 활성물질을 추출하였다. 이 추출액을 실리카겔 관 크로마토그래피, 분취 TLC, 분취 HPL를 하여 MPF 활성 억제 분획을 분리하였다.

• Animal cells and systems
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• v.2 no.1
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• pp.87-91
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• 1998

The present study investigated the involvement of the phospholipase C (PLC) and protein kinase C (PKC) signaling pathways during progesteroneinduced meiotic maturation in amphibian (Rana dybowskii) oocytes. Prosesterone-induced germinal vesicle breakdown (GVBD) of oocytes was significantly inhibited by a PKC inhibitor, staurosporine and a PLC inhibitor, U73122, in a dose-dependent manner. In contrast, U73343, an inactive analogue of U73122, was ineffective in suppressing GVBD. PKC activity in oocytes reached a maximum level at 30 min after progesterone stimulation and this elevated PKC activity was effectively suppressed by U73122 or staurosporine, suggesting that the activation of PKC enzyme is closely linked to PLC signaling during oocyte maturation. In addition, these inhib itors blocked the maturation promoting factor (MPF) activity which appeared in oocytes in response to progesterone, suggesting that PKC activation is an important signal for MPF activity. Therefore, this study demonstrates that the activation of PKC via PLC signaling is directly linked to an intracellular protein kinase cascade related to the appearance of MPF activity during meiotic maturation in amphibian (Rana dybowskii) oocytes.