核蛋白与分离的大鼠肝细胞核的ATP依赖性结合。

Imamoto-Sonobe N, Yoneda Y, Iwamoto R, Sugawa H, Uchida T

Institute for Molecular and Cellular Biology, Osaka University, Japan.

Proc Natl Acad Sci U S A. 1988 May;85(10):3426-30. doi: 10.1073/pnas.85.10.3426.

In vitro association of Xenopus nucleoplasmin and mammalian nonhistone chromosomal high mobility group 1 (HMG1) protein with nuclei isolated from rat liver was examined. Efficient association of nuclear proteins with isolated nuclei requires ATP, HCO3-, and Ca2+. Association occurred at 33 degrees C but not at 4 degrees C. ATP could be replaced by adenosine 5'-[alpha,beta-methylene]triphosphate (pp[CH2]pA), a nonhydrolyzable ATP analog. pp[CH2]pA associated with nuclei at 33 degrees C and nucleoplasmin and HMG1 rapidly associated with the pp[CH2]pA-bound nuclei at 4 degrees C. Competition studies showed that these associations at both 33 degrees C and 4 degrees C were specific. More than 80% of the bindings of nuclear proteins to the nuclear surface were blocked by wheat germ agglutinin.

研究了非洲爪蟾核质蛋白和哺乳动物非组蛋白染色体高迁移率族1（HMG1）蛋白与从大鼠肝脏分离的细胞核在体外的结合情况。核蛋白与分离细胞核的有效结合需要ATP、HCO₃⁻和Ca²⁺。结合在33℃时发生，但在4℃时不发生。ATP可用腺苷5'-[α,β-亚甲基]三磷酸（pp[CH₂]pA）替代，pp[CH₂]pA是一种不可水解的ATP类似物。pp[CH₂]pA在33℃时与细胞核结合，核质蛋白和HMG1在4℃时迅速与结合了pp[CH₂]pA的细胞核结合。竞争研究表明，在33℃和4℃时的这些结合都是特异性的。超过80%的核蛋白与核表面的结合被麦胚凝集素阻断。