PMID- 8843411
OWN - NLM
STAT- MEDLINE
DCOM- 19970408
LR  - 20081121
IS  - 0888-8809 (Print)
IS  - 0888-8809 (Linking)
VI  - 10
IP  - 8
DP  - 1996 Aug
TI  - Transcriptional activation and dimerization functions in the human vitamin D 
      receptor.
PG  - 945-57
AB  - The C-terminal domain of the human vitamin D receptor (hVDR) is essential for 
      dimerization with retinoid X receptors and for transcriptional activation. To 
      define the dimerization domain of the hVDR, a series of internal deletion mutants 
      of the receptor were prepared beginning within the E domain and extending through 
      the F domain to the C terminus. These mutant receptors were tested for 
      dimerization and transcriptional activities by means of gel shift assay and 
      beta-galactosidase assay, respectively, in a yeast system. The dimerization 
      domain of the hVDR was localized to two separate but adjacent regions of the 
      receptor molecule. In these experiments, the activation domain colocalized with 
      dimerization. To more precisely delineate a relationship between these domains, 
      region-specific random mutagenesis was carried out to detect mutants using 
      error-prone PCR and a functional screen strategy employed using transformed 
      yeast. Two classes of inactive receptors were identified: one in which both 
      transcriptional activation and dimerization were compromised and a second in 
      which only transcriptional activation was abolished. Most of the mutations 
      responsible for these phenotypes were single. The studies suggest a separation 
      between dimerization and transactivation domains. We reconstituted each of these 
      hVDR mutants in a mammalian expression vector and evaluated them individually in 
      COS-1 cells. All VDR mutants were transcriptionally active in this cellular 
      background in response to 1,25-dihydroxyvitamin D3 although the potency of the 
      hormone was reduced. The latter observation coincided with the observation that 
      each mutant was compromised to some extent in binding affinity. These data 
      clearly demonstrate the existence of an activation domain in hVDR that is 
      separable from the domain involved in dimerization. Factors that couple hVDR to 
      the general transcription apparatus in yeast through the activation domain in the 
      hVDR, however, appear to be unrelated or dissimilar to those used in COS-1 cells.
FAU - Jin, C H
AU  - Jin CH
AD  - Department of Skeletal Biology, Ligand Pharmaceuticals Inc., San Diego, 
      California 92121, USA.
FAU - Kerner, S A
AU  - Kerner SA
FAU - Hong, M H
AU  - Hong MH
FAU - Pike, J W
AU  - Pike JW
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Mol Endocrinol
JT  - Molecular endocrinology (Baltimore, Md.)
JID - 8801431
RN  - 0 (Receptors, Calcitriol)
RN  - 0 (Receptors, Retinoic Acid)
RN  - 0 (Retinoid X Receptors)
RN  - 0 (Transcription Factors)
RN  - 9007-49-2 (DNA)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - Cell Line
MH  - DNA/chemistry/metabolism
MH  - *Dimerization
MH  - Gene Deletion
MH  - Humans
MH  - Molecular Sequence Data
MH  - Mutagenesis
MH  - Receptors, Calcitriol/chemistry/genetics/*physiology
MH  - Receptors, Retinoic Acid/chemistry/metabolism
MH  - Retinoid X Receptors
MH  - Saccharomyces cerevisiae/genetics
MH  - Sequence Analysis
MH  - Structure-Activity Relationship
MH  - Transcription Factors/chemistry/metabolism
MH  - *Transcription, Genetic
MH  - Transcriptional Activation
EDAT- 1996/08/01 00:00
MHDA- 1996/08/01 00:01
CRDT- 1996/08/01 00:00
PHST- 1996/08/01 00:00 [pubmed]
PHST- 1996/08/01 00:01 [medline]
PHST- 1996/08/01 00:00 [entrez]
AID - 10.1210/mend.10.8.8843411 [doi]
PST - ppublish
SO  - Mol Endocrinol. 1996 Aug;10(8):945-57. doi: 10.1210/mend.10.8.8843411.