The vitamin D response element-binding protein. A novel dominant-negative regulator of vitamin D-directed transactivation.
Vitamin D resistance in certain primate genera is associated with the constitutive overexpression of a non-vitamin D receptor (VDR)-related, vitamin D response element-binding protein (VDRE-BP) and squelching of vitamin d-directed transactivation. We used DNA affinity chromatography to purify proteins associated with non-VDR-VDRE binding activity from vitamin d-resistant New World primate cells. In electrophoretic mobility shift assays, these proteins bound specifically to either single-strand or double-strand oligonucleotides harboring the VDRE. Amino acid sequencing of tryptic peptides from a 34-kDa (VDRE-BP1) and 38-kDa species (VDRE-BP-2) possessed sequence homology with human heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and hnRNPA2, respectively. cDNAs bearing the open reading frame for both VDRE-BPs were cloned and used to transfect wild-type, hormone-responsive primate cells. Transient and stable overexpression of the VDRE-BP2 cDNA, but not the VDRE-BP1 cDNA, in wild-type cells with a VDRE-luciferase reporter resulted in significant reduction in reporter activity. These data suggest that the hnRNPA2-related VDRE-BP2 is a dominant-negative regulator of vitamin D action.
Chen
H
H
Burns and Allen Research Institute and the Division of Endocrinology, Diabetes and Metabolism, Department of Pathology, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles, California 90048, USA.
Hu
B
B
Allegretto
E A
EA
Adams
J S
JS
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002427:Cebidae; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D005799:Genes, Dominant; D017930:Genes, Reporter; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012261:Ribonucleoproteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015533:Transcriptional Activation; D014162:Transfection; D014807:Vitamin D / Q000378:metabolism; D014809:Vitamin D-Binding Protein / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology
D002352:Carrier Proteins; D018076:DNA, Complementary; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D012261:Ribonucleoproteins; D014809:Vitamin D-Binding Protein; C417251:vitamin D response element-binding protein 2; D014807:Vitamin D; D004247:DNA; D008156:Luciferases