ERC-55, a binding protein for the papilloma virus E6 oncoprotein, specifically interacts with vitamin D receptor among nuclear receptors.
VDR regulates gene expression in a ligand-dependent way by binding to cognate enhancer elements of target gene promoters. The ligand-dependent activation function, AF-2, of VDR is thought to require transcriptional co-activators/co-repressors together with basal transcriptional machinery. Using a yeast two hybrid system with VDR, we have isolated a mouse Ca(2+)-binding protein (designated as VAF1) specifically interacting in vivo and in vitro with VDR among nuclear receptors like RAR, RXR, ER and GR. VAF1 is a mouse homologue to human ERC-55, which has recently been shown to interact with human papillomavirus oncogenic protein, E6[1]. Unlike those of many previously identified co-activators, the VDR-VAF1 interaction was ligand-independent. Thus, VAF1 seems a putative VDR-specific cofactor modulating its function.
Imai
T
T
Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
Matsuda
K
K
Shimojima
T
T
Hashimoto
T
T
Masuhiro
Y
Y
Kitamoto
T
T
Sugita
A
A
Suzuki
K
K
Matsumoto
H
H
Masushige
S
S
Nogi
Y
Y
Muramatsu
M
M
Handa
H
H
Kato
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D008969:Molecular Sequence Data; D009856:Oncogene Proteins, Viral / Q000378:metabolism*; D027383:Papillomaviridae / Q000378:metabolism*; D018167:Receptors, Calcitriol / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D009856:Oncogene Proteins, Viral; C088393:RCN2 protein, human; D018167:Receptors, Calcitriol; D011993:Recombinant Fusion Proteins; C106373:VAF1 protein, mouse; C093202:taipoxin-associated calcium-binding protein 49