Nordgård O, Dahle Ø, Andersen T Ø, Gabrielsen O S
Department of Biochemistry, University of Oslo, P.O. Box 1041 Blindern, 0316 Oslo, Norway.
Biochimie. 2001 Oct;83(10):969-71. doi: 10.1016/s0300-9084(01)01329-3.
The Jun activation domain binding protein 1 (JAB1) was first identified as an interaction partner and coactivator of c-Jun. Subsequently, it was found to be a subunit of the COP9 signalosome (CSN) and termed CSN subunit 5 (CSN5). This complex regulates light-mediated development in plants and plays an essential role in a variety of organisms. A striking feature of JAB1/CSN5 is its reported interaction with a wide range of proteins and its modulation of their activity or stability. We applied the yeast two-hybrid system to screen for proteins interacting with the DNA-binding domain of the transcription factor c-Myb and found JAB1/CSN5 among the double-positive clones. To our surprise JAB1/CSN5 was shown to interact with the DNA-binding domain of GAL4 alone and had to be rejected as a false positive in the GAL4-based two-hybrid system. This finding emphasizes the necessity of particular caution when JAB1/CSN5 is found in two-hybrid screenings.
Jun激活域结合蛋白1（JAB1）最初被鉴定为c-Jun的相互作用伴侣和共激活因子。随后，它被发现是COP9信号体（CSN）的一个亚基，并被命名为CSN亚基5（CSN5）。该复合体调节植物中的光介导发育，并在多种生物体中发挥重要作用。JAB1/CSN5的一个显著特征是其与多种蛋白质的相互作用以及对它们活性或稳定性的调节。我们应用酵母双杂交系统筛选与转录因子c-Myb的DNA结合域相互作用的蛋白质，并在双阳性克隆中发现了JAB1/CSN5。令我们惊讶的是，JAB1/CSN5被证明仅与GAL4的DNA结合域相互作用，因此在基于GAL4的双杂交系统中不得不被作为假阳性排除。这一发现强调了在双杂交筛选中发现JAB1/CSN5时特别谨慎的必要性。
