Nucleic Acids Research, Vol 24, Issue 4 566-572, Copyright © 1996 by Oxford University Press
AJ Salerno, Z He, A Goos-Nilsson, H Ahola and P Mak
Several members of the nuclear receptor superfamily including RXR (retinoid
X receptor) bind to a specific retinoic acid response element (site A) of
the apoAI promoter. However, transcriptional activation of the apoAI gene
by different homo- and heterodimeric forms of RXR or RAR (retinoic acid
receptors) cannot be evaluated in mammalian cells, which contain endogenous
RXR or RAR. In order to circumvent this limitation, we assessed the
DNA-binding activities and transcriptional activation of different homo-
and heterodimers of these receptors in yeast. Electrophoretic mobility
shift assays (EMSA) demonstrated that yeast expressed RARalpha does not
bind to site A of the apoAl promoter, whereas binding of RARbeta to site A
is ligand-dependent. Both RARalpha and RARbeta form heterodimers with
RXRalpha and bind to site A with high affinity. These DNA-binding studies
correlate with the transcriptional data, which indicated that RARbeta but
not RARalpha activates transcription from site A in response equally well
to 9-cis and all-trans retinoic acids. 9-cis RA is a more potent ligand
than all- trans RA to activate transcription via RXR/RAR heterodimers. We
conclude that this yeast expression system is a useful tool to elucidate
the 'transactivation code' for apoAl site A via specific combinations of
different homo and heterodimeric versions of RXR and RAR.
ARTICLES
Differential transcriptional regulation of the apoAI gene by retinoic acid receptor homo- and heterodimers in yeast
Wyeth-Ayerst Research, Lederle Laboratories, Pearl River, NY 10965, USA.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
Y.-K. Leung, P. Mak, S. Hassan, and S.-M. Ho Estrogen receptor (ER)-beta isoforms: A key to understanding ER-beta signaling PNAS, August 29, 2006; 103(35): 13162 - 13167. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. P. Olson and R. J. Koenig 5'-Flanking Sequences in Thyroid Hormone Response Element Half-sites Determine the Requirement of Retinoid X Receptor for Receptor-mediated Gene Expression J. Biol. Chem., April 11, 1997; 272(15): 9907 - 9914. [Abstract] [Full Text] [PDF] |
||||

