PMID- 7491109
OWN - NLM
STAT- MEDLINE
DCOM- 19960104
LR  - 20191210
IS  - 0888-8809 (Print)
IS  - 0888-8809 (Linking)
VI  - 9
IP  - 9
DP  - 1995 Sep
TI  - A highly conserved region in the hormone-binding domain of the human vitamin D 
      receptor contains residues vital for heterodimerization with retinoid X receptor 
      and for transcriptional activation.
PG  - 1166-79
AB  - Residues located between amino acids 244 and 263 in the human vitamin D receptor 
      (hVDR) show extensive homology with other members of the steroid/thyroid/retinoid 
      hormone receptor superfamily. The corresponding region of the glucocorticoid 
      receptor has been shown to interact with the 90-kilodalton heat shock protein 
      (hsp90), yet hVDR does not appear to bind to hsp90. Herein we report a study of 
      hVDR in which the functional role of five conserved residues was tested by 
      replacing Phe-244, Lys-246, Leu-254, Gln-259, and Leu-262 with glycines by 
      site-directed mutagenesis. Initial screening of these mutants indicated that all 
      were significantly impaired in their ability to activate transcription from a 
      vitamin D-responsive reporter construct when expressed in transfected 
      VDR-deficient COS-7 cells. Further characterization revealed two classes of 
      mutants: the predominant class binds the 1,25-dihydroxyvitamin D3 ligand normally 
      but is defective in its ability to form a heterodimeric complex with the retinoid 
      X receptor (RXR) on a vitamin D responsive element (VDRE). A second unique class, 
      represented by a single mutant at Lys-246, is normal both with respect to ligand 
      binding and complex formation but still very impaired in transactivation ability. 
      The distinction between these two classes was confirmed by the demonstration that 
      a member of the first class, with a mutation at Gln-259, could be restored to 
      near wild type transactivation ability by supplying excess RXR, while the Lys-246 
      mutant could not be so rescued. We therefore conclude that the primary function 
      of this conserved domain in hVDR is the mediation of heterodimerization with RXR, 
      leading to VDRE binding and transactivation. The possibility also exists that the 
      Lys-246 mutant may be impaired in a step of transactivation that is distal to 
      complex formation with RXR on the VDRE, perhaps in interactions with the 
      transcriptional machinery itself.
FAU - Whitfield, G K
AU  - Whitfield GK
AD  - Department of Biochemistry, University of Arizona College of Medicine, Tucson 
      85724, USA.
FAU - Hsieh, J C
AU  - Hsieh JC
FAU - Nakajima, S
AU  - Nakajima S
FAU - MacDonald, P N
AU  - MacDonald PN
FAU - Thompson, P D
AU  - Thompson PD
FAU - Jurutka, P W
AU  - Jurutka PW
FAU - Haussler, C A
AU  - Haussler CA
FAU - Haussler, M R
AU  - Haussler MR
LA  - eng
GR  - AR-15781/AR/NIAMS NIH HHS/United States
GR  - DK-33351/DK/NIDDK NIH HHS/United States
GR  - DK-40372/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Mol Endocrinol
JT  - Molecular endocrinology (Baltimore, Md.)
JID - 8801431
RN  - 0 (Hormones)
RN  - 0 (Macromolecular Substances)
RN  - 0 (Receptors, Calcitriol)
RN  - 0 (Receptors, Retinoic Acid)
RN  - 0 (Retinoid X Receptors)
RN  - 0 (Transcription Factors)
RN  - FXC9231JVH (Calcitriol)
SB  - IM
EIN - Mol Endocrinol 1995 Nov;9(11):1509
MH  - Amino Acid Sequence
MH  - Animals
MH  - Base Sequence
MH  - Binding Sites
MH  - Calcitriol/metabolism
MH  - Cell Line, Transformed
MH  - Chlorocebus aethiops
MH  - Conserved Sequence
MH  - Hormones/*metabolism
MH  - Humans
MH  - Kidney
MH  - Macromolecular Substances
MH  - Molecular Sequence Data
MH  - Mutagenesis, Site-Directed
MH  - Point Mutation
MH  - Receptors, Calcitriol/*chemistry/genetics/metabolism
MH  - Receptors, Retinoic Acid/*chemistry
MH  - Retinoid X Receptors
MH  - Simian virus 40
MH  - Structure-Activity Relationship
MH  - Transcription Factors/*chemistry
MH  - *Transcription, Genetic
MH  - Transfection
EDAT- 1995/09/01 00:00
MHDA- 1995/09/01 00:01
CRDT- 1995/09/01 00:00
PHST- 1995/09/01 00:00 [pubmed]
PHST- 1995/09/01 00:01 [medline]
PHST- 1995/09/01 00:00 [entrez]
AID - 10.1210/mend.9.9.7491109 [doi]
PST - ppublish
SO  - Mol Endocrinol. 1995 Sep;9(9):1166-79. doi: 10.1210/mend.9.9.7491109.