title: Isolation and characterization of axolotl NPDC-1 and its effects on retinoic acid receptor signaling.
abstract: Retinoic acid, a key morphogen in early vertebrate development and tissue regeneration, mediates its effects through the binding of receptors that act as ligand-induced transcription factors. These binding events function to recruit an array of transcription co-regulatory proteins to specific gene promoters. One such co-regulatory protein, neuronal proliferation and differentiation control-1 (NPDC-1), is broadly expressed during mammalian development and functions as an in vitro repressor of retinoic acid receptor (RAR)-mediated transcription. To obtain comparative and developmental insights about NPDC-1 function, we cloned the axolotl (Ambystoma mexicanum) orthologue and measured transcript abundances among tissues sampled during the embryonic and juvenile phases of development, and also during spinal cord regeneration. Structurally, the axolotl orthologue of NPDC-1 retained sequence identity to mammalian sequences in all functional domains. Functionally, we observed that axolotl NPDC-1 mRNA expression peaked late in embryogenesis, with highest levels of expression occurring during the time of limb development, a process regulated by retinoic acid signaling. Also similar to what has been observed in mammals, axolotl NPDC-1 directly interacts with axolotl RAR, modulates axolotl RAR DNA binding, and represses cell proliferation and axolotl RAR-mediated gene transcription. These data justify axolotl as a model to further investigate NPDC-1 and its role in regulating retinoic acid signaling.
authors.affiliation: Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone Ave., Lexington, KY 40536, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Theodosiou
authors.forename: James R
authors.initials: JR
authors.lastname: Monaghan
authors.forename: Michael L
authors.initials: ML
authors.lastname: Spencer
authors.forename: S Randal
authors.initials: SR
authors.lastname: Voss
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Noonan
mesh_terms: D000558:Ambystoma mexicanum / Q000235:genetics*; D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002460:Cell Line; D003001:Cloning, Molecular; D017931:DNA Primers; D020869:Gene Expression Profiling; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000502:physiology*; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D009419:Nerve Tissue Proteins; D018168:Receptors, Retinoic Acid