磷酸酶抑制剂花萼海绵诱癌素A对非洲爪蟾卵提取物中DNA复制起始的抑制作用。

Inhibition of initiation of DNA replication in Xenopus egg extracts by a phosphatase inhibitor, calyculin A.

作者信息

Someya A, Tanaka N, Okuyama A

机构信息

Applied Enzymology, Molecular Biology Research Laboratories, Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd., Japan.

出版信息

Biochem Biophys Res Commun. 1993 Oct 15;196(1):85-91. doi: 10.1006/bbrc.1993.2219.

DOI:10.1006/bbrc.1993.2219

PMID:8216339

Abstract

The protein phosphatase inhibitor calyculin A was found to strongly inhibit the DNA replication activity of Xenopus egg extracts in a dose-dependent manner. Calyculin A (0.8 nM) completely prevented the oscillation in DNA replication activity of mitotic extracts released by the addition of CaCl2. In contrast, in the case of extracts prepared from eggs activated by calcium ionophore A23187, calyculin A (0.8 nM) had no effect on the first peak of the oscillation in activity but inhibited the second peak of the oscillation. These results strongly suggest that calyculin A inhibits a protein phosphatase, which is involved in the initiation of DNA replication in the Xenopus egg extracts.

摘要

发现蛋白磷酸酶抑制剂花萼海绵诱癌素A能以剂量依赖的方式强烈抑制非洲爪蟾卵提取物的DNA复制活性。花萼海绵诱癌素A（0.8纳摩尔）完全阻止了因添加氯化钙而释放的有丝分裂提取物的DNA复制活性振荡。相反，在由钙离子载体A23187激活的卵制备的提取物中，花萼海绵诱癌素A（0.8纳摩尔）对活性振荡的第一个峰值没有影响，但抑制了振荡的第二个峰值。这些结果有力地表明，花萼海绵诱癌素A抑制了一种蛋白磷酸酶，该酶参与非洲爪蟾卵提取物中DNA复制的起始过程。