Mitogen-Activated Protein Kinase Kinase Inhibitor Suppresses Cyclin B1 Synthesis and Reactivation of p34cdc2 Kinase, Which Improves Pronuclear Formation Rate in Matured Porcine Oocytes Activated by Ca2+ Ionophore1
Mitogen-Activated Protein Kinase Kinase Inhibitor Suppresses Cyclin B1 Synthesis and Reactivation of p34cdc2 Kinase, Which Improves Pronuclear Formation Rate in Matured Porcine Oocytes Activated by Ca2+ Ionophore1
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丝裂原激活蛋白激酶激酶抑制剂抑制细胞周期蛋白 B1 合成和 p34cdc2 激酶重新激活，从而提高 Ca2 离子载体1 激活的成熟猪卵母细胞的原核形成率
作者：
J. Ito;M. Shimada;T. Terada
摘要为了探讨促分裂原活化蛋白激酶（MAPK）/MAP激酶级联反应对猪卵母细胞孤雌激活过程中p34 cdc 2激酶活性和细胞周期蛋白B1水平的影响，测定了不同浓度Ca 2+离子载体处理后猪卵母细胞的MEK活性、MAP激酶活性、p34 cdc 2激酶活性和细胞周期蛋白B1水平。高浓度的Ca 2+离子载体（50 μM）可迅速降低卵母细胞的MEK活性，培养时间长达8小时。10 μM处理组的MEK活性显著较高。低浓度处理短暂降低p34 cdc 2激酶活性，但不影响MAP激酶活性，并最终诱导p34 cdc 2激酶通过合成细胞周期蛋白B1的再激活。另一方面，高浓度的Ca 2+离子载体或低浓度的Ca 2+离子载体加MEK抑制剂，U 0126，线性降低MAP激酶活性的p34 cdc 2激酶活性的降低后，这些卵母细胞形成原核。这些结果表明，降低MAP激酶活性是必不可少的，以维持低p34 cdc 2激酶活性导致细胞周期蛋白B通过钙离子依赖性途径的降解; MAP激酶和p34 cdc 2激酶的活性较低诱导正常的减数分裂完成和孤雌激活的猪卵母细胞的原核形成。
Abstract To investigate the role of mitogen-activated protein (MAP) kinase kinase (MEK)/MAP kinase cascade on p34cdc2 kinase activity and cyclin B1 levels during parthenogenetic activation of porcine oocytes, MEK activity, MAP kinase activity, p34cdc2 kinase activity, and cyclin B1 levels were assayed in mature porcine oocytes after treatment with different concentrations of Ca2+ ionophore. A high concentration of Ca2+ ionophore (50 μM) rapidly reduced MEK activity in oocytes for up to 8 h of culture. MEK activity in the 10-μM treatment group was significantly higher. The low concentration treatment transiently decreased p34cdc2 kinase activity but did not affect MAP kinase activity and ultimately induced reactivation of p34cdc2 kinase via the synthesis of cyclin B1. On the other hand, treatments of a high concentration of Ca2+ ionophore or a low concentration of Ca2+ ionophore plus MEK inhibitor, U0126, linearly decreased MAP kinase activity following the decrease of p34cdc2 kinase activity; most of these oocytes formed pronuclei. These results suggest that decreasing MAP kinase activity is essential to maintaining low p34cdc2 kinase activity resulting from the degradation of cyclin B via a Ca2+-dependent pathway; lower activities of both MAP kinase and p34cdc2 kinase induce normal meiotic completion and pronuclear formation of parthenogenetically activated porcine oocytes.
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影响因子：
4.6
作者：
H. Hochegger;A. Klotzbücher;J. Kirk;M. Howell;K. Le Guellec;K. Fletcher;T. Duncan;Muhammad Sohail;T. Hunt
通讯作者：
H. Hochegger;A. Klotzbücher;J. Kirk;M. Howell;K. Le Guellec;K. Fletcher;T. Duncan;Muhammad Sohail;T. Hunt
c-mos 基因产物是小鼠卵减数分裂过程中细胞周期蛋白 B 积累所必需的。
DOI：
10.1073/pnas.88.17.7869
发表时间：
1991
影响因子：
11.1
作者：
O'Keefe,SJ;Kiessling,AA;Cooper,GM
通讯作者：
Cooper,GM
影响因子：
2.7
作者：
KLINE, D;KLINE, JT
通讯作者：
KLINE, JT
用钙离子载体孤雌激活猪卵母细胞，并在激活后阻止精子穿透。
影响因子：
3.6
作者：
Wang,WH;Macháty,Z;Abeydeera,LR;Prather,RS;Day,BN
通讯作者：
Day,BN
影响因子：
3.6
作者：
MOOS, J;VISCONTI, PE;KOPF, GS
通讯作者：
KOPF, GS