9-cis Retinoic Acid Stereoisomer Binds and Activates the Nuclear Receptor RXRα
of outstanding interest, A ligand isolation method termed ‘ligand trapping’ was developed to isolate the ligand for RXR. A stereoisomer of retinoic acid, 9-cis retinoic acid, was identified to be the high affinity ligand for RXR.
Intracellular Signaling by 14-Hydroxy-4,14-Retro-retinol
of special interest, A metabolite of retinol (vitamin A) but not retinoic acid was shown to be active in preventing necrotic cell death of activated immune cells. The identification of this metabolite was determined and it is 14-hydroxy-4, 14-retro-retinol.
Direct Repeats as Selective Response Elements for the Thyroid Hormone, Retinoic Acid, and Vitamin D3 Receptors
of outstanding interest, This paper suggests that VDR, thyroid hormone receptor, and RAR may exhibit selective binding and activation of response elements as direct repeats of half sites with a spacing preference of three, four and five bp, respectively. It was suggested that this is a role of the receptors and pertained to physiologically occuring sites.
The Orientation and Spacing of Core-DNA Binding Motifs Dictate Selective Transcriptional Responses to Three Nuclear Receptors
of outstanding interest, In this study, ER, RAR and thyroid hormone receptor were shown to exhibit distinct DNA binding and functional preferences with regard to the orientation and spacing of core binding motifs in hormone response elements, potentially constituting a code by which nuclear receptors recognizing similar half sites could distinguish between response elements.
RXR Beta: a Co-regulator that Enhances Binding of Retinoic Acid, Thyroid Hormone, and Vitamin D Receptors to Their Cognate Response Elements
of outstanding interest, A strategy of sequential screening of expression libraries with a RA response element and RAR identified RXRβ as a coregulator for RXR. RXR α and β form heterodimers with RAR, preferentially increasing its DNA binding and transcriptional activity on promoter containing RA response element. Remarkably, RXR also heterodimerizes with thyroid hormone and vitamin D receptors, increasing both DNA binding and transcriptional function on their respective response elements. See also [10••, 32–36].
H-2RIIBP (RXR β) Heterodimerization Provides a Mechanism for Combinatorial Diversity in the Regulation of Retinoic Acid and Thyroid Hormone Responsive Genes
Half-site Spacing and Orientation Determines Whether Thyroid Hormone and Retinoic Acid Receptors and Related Factors Bind to DNA Response Elements as Monomers, Homodimers, or Heterodimers
Participation of Non-zinc Finger Residues in DNA Binding by Two Nuclear Orphan Receptors
of special interest, A region immediately carboxy terminal to the DNA-binding domain was identified that confers binding site preference on NGF1B and RXRβ. This subclass of nuclear receptors may utilize a distinct domain for increased DNA-binding specificity, in contrast to the steroid members of the family, in which this stretch of amino acids does not appear to contribute to DNA binding. See also [26].
Chromosomal Translocation t(15; 17) in Human Acute Promyelocytic Leukemia Fuses RAR α with a Novel Putative Transcription Factor, PML
of special interest, A unique mRNA product in leukemic cells from a t(15; 17) acute promyelocytic leukemia patient encodes a fusion protein of RARa and a myeloid gene product PML. See also [45•,46•].
The PML-RAR a Fusion mRNA Generated by the t(15; 17) Translocation in Acute Promyelocytic Leukemia Encodes a Functionally Altered RAR
of special interest, The t(15; 17) translocation in APL generates a PML-RAR fusion protein that could contribute to leukemogenesis through interference with promyelocytic differentiation. See also [44•, 46•].
Structure, Localization and Transcriptional Properties of Two Classes of Retinoic Acid Receptor a Fusion Proteins in Acute Promyclocytic Leukemia (APL): Structural Similarities with a New Family of Oncoproteins
Dopamine Activation of an Orphan of the Steroid Receptor Superfamily
of special interest, The chicken ovalbumin upstream promoter transcription factor, an orphan nuclear receptor, was shown to be activated by physiological concentrations of the membrane-bound receptor agonist, dopamine.
Dopaminergic and Ligand-independent Activation of Steroid Hormone Receptors
of special interest, In vitro, dopamine faithfully mimicked the effect of progesterone in activating progesterone receptor. Dual activation by progesterone and dopamine was dissociable, and a serine residue in the progesterone receptor was identified that is not necessary for progesteronedependant activation of the receptor, but is essential for dopamine activation.
