CRABP-1, Cellular retinoic acid binding

Abbreviations used in this review APL, acute promyelocytic leukaemia CEF, chick embryo fibroblasts CRABP, cellular retinoic acid-binding protein ODC, ornithine decarboxylase RA, retinoic acid RARE, retinoic acid responsive element RAR, retinoic acid receptor RXR, retinoid X receptor TEMPO, 2,2,6,6-tetramethylpiperidine Y-oxide TOC, tracheal organ culture TPA, 12-<2-tetradecanoylphorbol-13-acetate TTNN, 6-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-2-naphthanoic acid TTNPB, 4-((.Q-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2- naphthyl)propenyl)benzoic acid. 

Anhydroretinol binds to plasma and intracellular RBPs, but not to the cellular retinoic acid binding proteins (CRABPs) or retinoid receptors. In experimental animals, it protects against the development of chemically induced tumors while showing none of the toxic effects of other retinoids. 

Retinoic acid may either enter the target cell from the circulation or may be formed intraceUularly by oxidation of retinol. A number of tissues - but not muscle, kidneys, small intestines, liver, lungs, or spleen - have a cellular retinoic acid binding protein (CRABP) that is distinct from CRBP. Testis and... 

Momoi T, Hanaoka K, and Momoi M (1990) Spatial and temporal expression of cellular retinoic acid binding protein (CRABP) along the anteroposterior axis in the central nervous system of mouse embryos. Biochemical and Biophysical Research Communications 169, 991-6. 

Many hydrophobic molecules such as vitamin A, vitamin D and steroid hormones play vital roles in a variety of cellular processes. Because of the low solubility of these molecules in water, it has been difficult to measure the binding properties of the site-directed mutants of the proteins that interact with these hydrophobic ligands such as cellular retinoic acid binding proteins (CRABPs) (Zhang et al. 1992 Chen et al. 1995). This has greatly hampered the studies of the quantitative structure-function relationships of these important proteins. 

Cellular retinoic acid-binding protein CRABP Not determined Sundeiin et al. (1985)... 

Retinoic acids, particularly trans-RA, bind with high affinity to cellular retinoic acid binding proteins I and II (CRABPI and CRABPII). Like the CRBPs, CRABPs are widely ex-... 

Oxidation of retinol produces retinoic acid tretinoin). The reaction is irreversible. Retinoic acid enters the portal blood, is transported bound to albumin, and is not stored to any great extent. The concentration of retinoic acid in plasma is normally 3-4 ng/mL. A biologically active metabolite, 5,6-epoxyretinoic acid, has been isolated from the intestinal mucosa of vitamin A-deficient rats following administration of H-retinoic acid. Several tissues have specific cellular retinoic acid-binding proteins (CRABPs). 

Maden, M., Horton, C., Graham, A., Leonard, L., Pizzey, J., Siegenthaler, G., Lumsden, A., Eriksson, U. 1992. Domains of cellular retinoic acid-binding protein I (CRABP I) expression in the hindbrain and neural crest of the mouse embryo. Mech. Dev. 37, 13-23. 

Cellular retinoic acid binding proteins (CRABPs) 32... 

Cellular retinoic acid binding proteins have been found in chickens, bovines, rats, mice, and humans and multiple isoforms identified. CRABP is a small protein (MW 15 kDa) [159] and the gene encoding CRABP has been... 

Retinoids present within a given cell are bound by intracellular-binding proteins, such as cellular retinol-binding proteins (CRBPs) or cellular retinoic acid-binding proteins (CRABPs) (Figure 1.2), all of which exhibit extremely high affinities for their substrates (Noy 2000). CRBP-I, for example, protects retinol from oxidation... 

Boylan, J F. and Gudas, L. J. (1991) Overexpression of the cellular retinoic acid binding protein-I (CRABP-I) results in a reduction in differentiation-specific gene expression in F9 teratocarcinoma cells J Cell Biol. 112, 965-979. 

The protocol presented in this chapter is derived from previously published methods (1,2). It has been used to investigate the effects of retinoic acid (RA) on the expression of cellular retinoic-acid binding protein (CRABP) -I and -II m relatively early mouse embryos (6.5-9.5-d postcoitum [p.c.] E6.5-9.5 /57)> Unfortunately, the size of the tissue sample that can be used for whole-mount ISH is limited, since both a riboprobe and an antibody-enzyme conjugate must penetrate the specimen and the unbound excess of both must be removed. Early embryos are small enough to allow penetration and removal of probe and antibody. This procedure should also work well for isolated pieces of larger embryos. 

Astrom, A, Tavakkol, A, Pettersson, U, Cromie, M, Elder, J. T., and Voorhees, J J (1991) Molecular-cloning of 2 human cellular retinoic acid-binding proteins (CRABP)—retinoic acid-induced expression of CRABP-II but not CRABP-I in adult human skin in vivo and in skin fibroblasts m vitro. J Biol Chem 266, 17,662-17,666... 

Nuclear-retinoid receptors provide a mechanism of retinoid action, but most likely where expressed, the cytosolic cellular retinoic acid-binding proteins (CRABPs) also affect the ability of retinoids to initiate biological signals (1,2). holo-CBlABP I sequesters retinoic acid (RA) with a value that may be <1 nM, and serves as a high-affinity 2 nM), efficient substrate of RA... 

Fiorella, P F and Napoli, J L (1991) Expression of cellular retinoic acid binding protein (CRABP) in Escherichia coli characterization and evidence that holo-CRABP is a substrate in retinoic acid metabolism J. Biol Chem 266, 16,572-16,579. 

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