Hormone-dependent translocation of vitamin D receptors is linked to transactivation

被引:82
作者
Racz, A [1 ]
Barsony, J [1 ]
机构
[1] NIDDK, Lab Cell Biochem & Biol, NIH, Bethesda, MD 20892 USA
关键词
D O I
10.1074/jbc.274.27.19352
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Vitamin D receptor (VDR) acts as a transcription factor mediating genomic actions of calcitriol. Our earlier studies suggested that calcitriol induces translocation of cytoplasmic VDR, but the physiologic relevance of this finding remained uncertain. Previous studies demonstrated that the activation function 2 domain (AF-2) plays an essential role in VDR transactivation. To elucidate hormone-dependent VDR translocation and its role, we constructed green fluorescent protein (GFP) chimeras with full-length VDR (VDR-GFP), AF-2-truncated VDR (AF-2del-VDR-GFP), and ligand-binding domain LBD)-truncated VDR (LBDdel-VDR-GFP), COS-7 cells were transiently transfected with these constructs. Western blot analysis, fluorescent microscopy, and transactivation assays showed that the generated chimeras are expressed and fluoresce and that VDR-GFP is transcriptionally active. After hormone treatment, cytoplasmic VDR-GFP translocated to the nucleus in a concentration-, time-, temperature-, and analog-specific manner. Hormone dose-response relationships for translocation and for transactivation were similar. Truncation of LED and truncation of AF-2 each abolished hormone-dependent translocation and transactivation. Our data confirm a hormone-dependent VDR translocation, demonstrate that an intact AF-2 domain is required for this translocation, and indicate that translocation is part of the receptor activation process.
引用
收藏
页码:19352 / 19360
页数:9
相关论文
共 44 条
[1]   INTRACELLULAR-LOCALIZATION AND TRANSLOCATION OF 1-ALPHA, 25-DIHYDROXYVITAMIN-D3 RECEPTOR IN OSTEOBLASTS [J].
AMIZUKA, N ;
OZAWA, H .
ARCHIVES OF HISTOLOGY AND CYTOLOGY, 1992, 55 (01) :77-88
[2]   A highly sensitive method for large-scale measurements of 1,25-dihydroxyvitamin D [J].
Arbour, NC ;
Ross, TK ;
Zierold, C ;
Prahl, JM ;
DeLuca, HF .
ANALYTICAL BIOCHEMISTRY, 1998, 255 (01) :148-154
[3]   IMMUNOCYTOLOGY WITH MICROWAVE-FIXED FIBROBLASTS SHOWS 1-ALPHA,25-DIHYDROXYVITAMIN-D3-DEPENDENT RAPID AND ESTROGEN-DEPENDENT SLOW REORGANIZATION OF VITAMIN-D RECEPTORS [J].
BARSONY, J ;
PIKE, JW ;
DELUCA, HF ;
MARX, SJ .
JOURNAL OF CELL BIOLOGY, 1990, 111 (06) :2385-2395
[4]   Subcellular distribution of normal and mutant vitamin D receptors in living cells - Studies with a novel fluorescent ligand [J].
Barsony, J ;
Renyi, I ;
McKoy, W .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1997, 272 (09) :5774-5782
[5]   ABSENT INTESTINAL RESPONSE TO CALCIFEROLS IN HEREDITARY RESISTANCE TO 1,25-DIHYDROXYVITAMIN-D - DOCUMENTATION AND EFFECTIVE THERAPY WITH HIGH-DOSE INTRAVENOUS CALCIUM INFUSIONS [J].
BLIZIOTES, M ;
YERGEY, AL ;
NANES, MS ;
MUENZER, J ;
BEGLEY, MG ;
VIEIRA, NE ;
KHER, KK ;
BRANDI, ML ;
MARX, SJ .
JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM, 1988, 66 (02) :294-300
[6]   Evidence using a green fluorescent protein-glucocorticoid receptor chimera that the RAN/TC4 GTPase mediates an essential function independent of nuclear protein import [J].
Carey, KL ;
Richards, SA ;
Lounsbury, KM ;
Macara, IG .
JOURNAL OF CELL BIOLOGY, 1996, 133 (05) :985-996
[7]   IMMUNOCYTOCHEMICAL LOCALIZATION OF THE 1,25-DIHYDROXYVITAMIN-D3 RECEPTOR IN TARGET-CELLS [J].
CLEMENS, TL ;
GARRETT, KP ;
ZHOU, XY ;
PIKE, JW ;
HAUSSLER, MR ;
DEMPSTER, DW .
ENDOCRINOLOGY, 1988, 122 (04) :1224-1230
[8]   Recent advances in the molecular biology of vitamin D action [J].
Darwish, HM ;
DeLuca, HF .
PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY, VOL 53, 1996, 53 :321-344
[9]   Visualization of Pit-1 transcription factor interactions in the living cell nucleus by fluorescence resonance energy transfer microscopy [J].
Day, RN .
MOLECULAR ENDOCRINOLOGY, 1998, 12 (09) :1410-1419
[10]  
DeLuca H F, 1985, Soc Gen Physiol Ser, V39, P159