Regulation of the amino-terminal transcription activation domain of progesterone receptor by a cofactor-induced protein folding mechanism.
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.
Wardell
Suzanne E
SE
Molecular Biology Program, University of Colorado Health Sciences Center, Aurora, USA.
Kwok
Stanley C
SC
Sherman
Lori
L
Hodges
Robert S
RS
Edwards
Dean P
DP
D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D010449:Peptide Mapping; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D051381:Rats; D011980:Receptors, Progesterone / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation
C106160:Jdp2 protein, rat; D011980:Receptors, Progesterone; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins