作为MPF的负调节剂,INH是蛋白酸酶2A的一种形式
T H Lee1, M J Solomon, M C Mumby
1Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
Cell
|January 25, 1991
概括
成熟促进因子 (MPF) 驱动细胞周期的进展. 这项研究确定INH是蛋白酸酶2A,它通过去化关键子单元来禁用MPF,反对细胞循环激活.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 成熟促进因子 (MPF) 对于真核细胞的G2到M阶段过渡至关重要.
- MPF的激活涉及p34cdc2的脱化,但其无活化途径尚不清楚.
- 鉴定出INH是Xenopus卵细胞中MPF前激活的抑制剂.
研究的目的:
- 阐明INH在MPF调节中的分子身份和功能.
- 调查INH在MPF失活中的作用.
- 了解INH反对MPF激活的机制.
主要方法:
- 从Xenopus卵细胞中净化INH.
- 生物化学测试以评估INH的酸酶活性.
- 在体外激活使用INH和蛋白酸酶2A (PP2A) 隔离的p34cdc2-cyclin复合体.
- 对p34cdc2和环林子单元的蛋白质脱化分析.
主要成果:
- INH经过净化,被确定为一种蛋白质酸酶2A的形式.
- 无论是INH还是PP2A的催化子单元,都直接失活了分离的p34cdc2-cyclin复合体.
- 不活化与循环素和p34cdc2子单元的脱化相关.
- 脱化发生在p34cdc2上的特定位置,反映了关键激活步骤.
结论:
- INH作为蛋白酸酶2A的功能,反对MPF激活.
- 通过逆转p34cdc2.2.的临界酸化,INH使MPF失活.
- 这种脱化机制是调节G2到M相过渡的关键.
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