INDUCTION OF STARFISH OOCYTE MATURATION BY THE BETA-GAMMA SUBUNIT OF STARFISH G-PROTEIN AND POSSIBLE EXISTENCE OF THE SUBSEQUENT EFFECTOR IN CYTOPLASM
INDUCTION OF STARFISH OOCYTE MATURATION BY THE BETA-GAMMA SUBUNIT OF STARFISH G-PROTEIN AND POSSIBLE EXISTENCE OF THE SUBSEQUENT EFFECTOR IN CYTOPLASM
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DOI：
10.1091/mbc.4.10.1027
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发表时间：
1993-10-01
影响因子：
3.3
通讯作者：
HOSHI, M
中科院分区：
文献类型：
--
作者：
CHIBA, K;KONTANI, K;HOSHI, M
从海星卵母细胞中纯化了G蛋白的β - γ亚基，并研究了它们在1-甲基腺嘌呤诱导卵母细胞成熟中的作用。将纯化后的海星G蛋白β - γ亚基注入海星卵母细胞后，其诱导生发囊泡破裂（GVBD）的速度快于牛脑G蛋白。将β - γ注射到生发囊附近的细胞质中比注射到生发囊或质膜附近的细胞质中更早地诱导GVBD。即使在GVBD后，荧光标记的β - γ仍保留在注射区域。注射β - γ还能诱导成熟促进因子的形成以及组蛋白H1激酶活性的增加。这些结果表明，β - γ通过1-甲基腺嘌呤的刺激与α -亚基分离，并与细胞质效应物相互作用，从而导致活性cdc2激酶的形成。
beta gamma subunits of G proteins were purified from starfish oocytes, and their role in the induction of oocyte maturation by 1-methyladenine was investigated. When injected into starfish oocytes, the purified beta gamma subunit of the starfish G protein induced germinal vesicle breakdown (GVBD) faster than that of bovine brain G protein. Injection of the starfish beta gamma into cytoplasm near the germinal vesicle (GV) induced GVBD earlier than when injected into the GV or the cytoplasm near the plasma membrane. Fluorescent-labeled beta gamma was retained in the injected area even after GVBD. Injected beta gamma also induced the formation of maturation-promoting factor as well as an increase of histone H1 kinase activity. These results suggest that beta gamma dissociates from alpha-subunit by the stimulation of 1-methyladenine and interacts with a cytoplasmic effector, which results in formation of active cdc2 kinase.