RETINOID-X-RECEPTOR-ALPHA FORMS TETRAMERS IN SOLUTION

Citation
S. Kersten et al., RETINOID-X-RECEPTOR-ALPHA FORMS TETRAMERS IN SOLUTION, Proceedings of the National Academy of Sciences of the United Statesof America, 92(19), 1995, pp. 8645-8649
Citations number
39
Categorie Soggetti
Multidisciplinary Sciences
ISSN journal
00278424
Volume
92
Issue
19
Year of publication
1995
Pages
8645 - 8649
Database
ISI
SICI code
0027-8424(1995)92:19<8645:RFTIS>2.0.ZU;2-M
Abstract
Protein-protein interactions allow the retinoid X receptor. (RXR) to b ind to cognate DNA as a homo- or a heterodimer and to participate in m ediating the effects of a variety of hormones on gene transcription. H ere we report a systematic study of the oligomeric state of RXR in the absence of a DNA template. We have used electrophoresis under nondena turing conditions and chemical crosslinking to show that in solution, RXR alpha forms homodimers as well as homotetramers. The dissociation constants governing dimer and tetramer formation were estimated by flu orescence anisotropy studies. The results indicate that RXR tetramers are formed with a high affinity and that at protein concentrations hig her than about 70 nM, tetramers will constitute the predominant specie s; Tetramer formation may provide an additional level of the regulatio n of gene transcription mediated by RXRs.