培养的烟草组织中的一种可溶的生长素结合蛋白可刺激体外的 RNA 合成。

A soluble auxin-binding protein from cultured tobacco tissues stimulates RNA synthesis in vitro.

机构信息

Department of Plant Morphogenesis, Botanisch Laboratorium, Rijksuniversiteit Leiden, Nonnensteeg 3, NL-2311 VJ, Leiden, The Netherlands.

出版信息

Planta. 1984 Feb;160(2):102-8. doi: 10.1007/BF00392857.

DOI:10.1007/BF00392857

PMID:24258411

Abstract

When the soluble auxin receptor from tobacco callus was isolated according to H. Oostrom et al. (1975, FEBS Lett. 59, 194-197; 1980, Planta 149, 44-47) a high polyphenol contamination in the receptor preparation was observed. We developed a new isolation procedure, which drastically reduced this contamination. The receptor, which was partially purified on Sephadex G-200, exhibited the same time- and temperature-dependent binding kinetics as described before (Oostrom et al. 1975, 1980). The Ka for indole-3-acetic acid (IAA) at 25°C was about 1.6·10(8) M(-1) and the number of binding sites varied from 0 to 2·10(-13) M mg(-1) protein. Addition of partially purified receptor preparations to isolated tobaccocallus nuclei resulted in an IAA-dependent stimulation of transcription, which was not observed with similar preparations that did not contain detectable amounts of specific IAA-binding sites. The average stimulation in the presence of 1 μM IAA was 42%; it was achieved by an increase in RNA-polymerase-II activity. The stimulation was not dependent upon the presence of 1 μM IAA during the isolation of the nuclei.

摘要

当根据 H. Oostrom 等人（1975 年，FEBS Lett. 59，194-197；1980 年，Planta 149，44-47）从烟草愈伤组织中分离出可溶性生长素受体时，发现受体制剂中存在高浓度的多酚污染。我们开发了一种新的分离程序，大大降低了这种污染。该受体在 Sephadex G-200 上进行部分纯化后，表现出与以前描述的相同的时间和温度依赖性结合动力学（Oostrom 等人，1975 年，1980 年）。在 25°C 时，吲哚-3-乙酸（IAA）的 Ka 值约为 1.6·10(8) M(-1)，结合位点数量从 0 到 2·10(-13) M mg(-1)蛋白不等。将部分纯化的受体制剂添加到分离的烟草愈伤组织核中，会导致 IAA 依赖性转录的刺激，而在不含有可检测量的特异性 IAA 结合位点的类似制剂中则没有观察到这种刺激。在 1 μM IAA 的存在下，平均刺激为 42%；这是通过增加 RNA 聚合酶-II 活性实现的。刺激不依赖于核分离过程中 1 μM IAA 的存在。