Structure and function of cytoplasmic retinoid binding proteins.
We examined the ligand protein interactions of two highly homologous cellular retinol binding proteins, CRBP and CRBP-II, and two highly homologous cellular retinoic acid binding proteins, CRABP-I and CRABP-II. While the crystal structures of all four have been determined, nuclear magnetic resonance studies provide a means for observing dynamic aspects of ligand protein interactions of these proteins in solution. The cellular functions of these proteins are less well understood. We have modeled retinoid flux between cytoplasmic retinoid proteins and model membranes and with nuclear receptors. Based on our in vitro studies, we propose that certain retinoids may indirectly influence retinoid signaling by displacing endogenous retinoids from the cytoplasmic proteins to the nuclear receptors.
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Department of Medicine, Washington University, School of Medicine, St. Louis, MO 63110, USA.
D003593:Cytoplasm / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011485:Protein Binding; D018168:Receptors, Retinoic Acid / Q000737:chemistry; D012177:Retinol-Binding Proteins / Q000737:chemistry* / Q000502:physiology*; D054840:Retinol-Binding Proteins, Cellular
D018168:Receptors, Retinoic Acid; D012177:Retinol-Binding Proteins; D054840:Retinol-Binding Proteins, Cellular; C082927:retinoic acid binding protein I, cellular; C082928:retinoic acid binding protein II, cellular