title: Response element binding proteins and intracellular vitamin D binding proteins: novel regulators of vitamin D trafficking, action and metabolism.
abstract: Using vitamin D-resistant New World primates as model of natural diversity for sterol/steroid action and metabolism, two families of novel intracellular vitamin D regulatory proteins have been discovered and their human homologs elucidated. The first family of proteins, heterogeneous nuclear ribonucleoproteins (hnRNPs), initially considered to function only as pre-mRNA-interacting proteins, have been demonstrated to be potent cis-acting, trans-dominant regulators of vitamin D hormone-driven gene transactivation. The second group of proteins bind 25-hydroxylated vitamin D metabolites. Their overexpression increases vitamin D receptor (VDR)-directed target gene expression. We found that these intracellular vitamin D binding proteins (IDBPs) are homologous to proteins in the heat shock protein-70 family. Our ongoing studies indicate directly or indirectly through a series of protein interactions that the IDBPs interact with hydroxylated vitamin D metabolites and facilitate their intracellular targeting.
authors.affiliation: The Burns and Allen Research Institute, Cedars-Sinai Medical Center, UCLA School of Medicine, B131, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA, USA.
authors.forename: John S
authors.initials: JS
authors.lastname: Adams
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Rene
authors.initials: R
authors.lastname: Chun
authors.forename: Mercedes A
authors.initials: MA
authors.lastname: Gacad
authors.forename: Carlos
authors.initials: C
authors.lastname: Encinas
authors.forename: Songyang
authors.initials: S
authors.lastname: Ren
authors.forename: Lisa
authors.initials: L
authors.lastname: Nguyen
authors.forename: Shaoxing
authors.initials: S
authors.lastname: Wu
authors.forename: Martin
authors.initials: M
authors.lastname: Hewison
authors.forename: Julia
authors.initials: J
authors.lastname: Barsony
mesh_terms: D000818:Animals; D004196:Disease Outbreaks; D006801:Humans; D012279:Rickets / Q000453:epidemiology; D014807:Vitamin D / Q000378:metabolism*; D014809:Vitamin D-Binding Protein / Q000378:metabolism*
chemical_list: D014809:Vitamin D-Binding Protein; D014807:Vitamin D