Wardell Suzanne E, Kwok Stanley C, Sherman Lori, Hodges Robert S, Edwards Dean P
Molecular Biology Program, University of Colorado Health Sciences Center, Aurora, USA.
Mol Cell Biol. 2005 Oct;25(20):8792-808. doi: 10.1128/MCB.25.20.8792-8808.2005.
We previously identified a small basic leucine zipper (bZIP) protein, Jun dimerization protein 2 (JDP-2), that acts as a coregulator of the N-terminal transcriptional activation domain of progesterone receptor (PR). We show here that JDP-2, through interaction with the DNA binding domain (DBD), induces or stabilizes structure in the N-terminal domain in a manner that correlates with JDP-2 stimulation of transcriptional activity. Circular dichroism spectroscopy experiments showed that JDP-2 interaction caused a significant increase in overall helical content of a two-domain PR polypeptide containing the N-terminal domain and DBD and that the change in structure resides primarily in the N-terminal domain. Thermal melt curves showed that the JDP-2/PR complex is significantly more stable than either protein alone, and partial proteolysis confirmed that JDP-2 interaction alters conformation of the N-terminal domain of PR. Functional analysis of N-terminal domain mutants and receptor chimeras provides evidence that the stimulatory effect of JDP-2 on transcriptional activity of PR is mediated through an interdomain communication between the DBD and the N-terminal domain and that transcriptional activity and functional response to JDP-2 are mediated by multiple elements of the N-terminal domain as opposed to a discrete region.
我们之前鉴定出一种小的碱性亮氨酸拉链（bZIP）蛋白，即Jun二聚化蛋白2（JDP-2），它作为孕激素受体（PR）N端转录激活域的共调节因子发挥作用。我们在此表明，JDP-2通过与DNA结合域（DBD）相互作用，以一种与JDP-2对转录活性的刺激相关的方式诱导或稳定N端结构域中的结构。圆二色光谱实验表明，JDP-2的相互作用导致包含N端结构域和DBD的两结构域PR多肽的整体螺旋含量显著增加，并且结构变化主要存在于N端结构域中。热熔曲线表明，JDP-2/PR复合物比单独的任何一种蛋白都显著更稳定，部分蛋白酶解证实JDP-2的相互作用改变了PR N端结构域的构象。N端结构域突变体和受体嵌合体的功能分析提供了证据，表明JDP-2对PR转录活性的刺激作用是通过DBD和N端结构域之间的结构域间通讯介导的，并且对JDP-2的转录活性和功能反应是由N端结构域的多个元件介导的，而不是由一个离散区域介导的。
