title: Characterization of steroid receptor coactivator in sea urchin, Strongylocentrotus nudus, and its involvement in embryonic development.
abstract: Ligand-bound nuclear receptors (NRs) recruit coactivators such as members of the p160 steroid receptor coactivator (SRC) family and cyclic AMP responsive element binding protein (CREB)-binding protein (CBP) to specific enhancer elements and activate target gene transcription. In the present study, we isolated a novel SRC from the sea urchin Strongylocentrotus nudus (SnSRC) by using the ligand-binding domain of retinoid X receptor as a bait in a yeast two-hybrid screening. The SnSRC and vertebrate SRCs are different in size but share the overall characteristic domains, such as NR interacting domain (NID), CBP-binding and glutamine-rich regions. SnSRC mRNA showed highest expression levels at the 32-cell, 64-cell and pluteus larval stages. Full-length SnSRC (1992 amino acids) interacted with several NRs, including sea urchin estrogen receptor-related receptor (ERR), human and masu salmon estrogen receptors (ERα), mouse ERRγ, rat glucocorticoid receptor α, and rat thyroid receptor β. The SnSRC possesses two functional NIDs, both of which are dependent on their core LxxLL motifs. Furthermore, preferential interacting domains for ERα in the SnSRC are located in the central LxxLL motifs, revealed by the truncation and mutagenesis studies. Strikingly, the SnSRC has a single transcription activation domain, which interacts with CBP, a transcriptional integrator. In addition, transient knockdown of the SnSRC gene in the sea urchin embryo using morpholino antisense RNA induced abnormal phenotypes at gastrulation stage such as the lack of primary invagitation and exogastrulation. These results suggest that the SnSRC is a new member of the SRC family and plays an important role during early embryonic development.
authors.affiliation: Department of Marine Molecular Biotechnology, Gangneung-Wonju National University, Gangneung 210-702, Republic of Korea.
authors.forename: Mi Ae
authors.initials: MA
authors.lastname: Kim
authors.forename: Gil Jung
authors.initials: GJ
authors.lastname: Kim
authors.forename: Sejung
authors.initials: S
authors.lastname: Maeng
authors.forename: Deuk-Hee
authors.initials: DH
authors.lastname: Jin
authors.forename: Young Chang
authors.initials: YC
authors.lastname: Sohn
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000378:metabolism*; D047108:Embryonic Development / Q000187:drug effects / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D056920:Nuclear Receptor Coactivator 1 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D047269:Strongylocentrotus / Q000187:drug effects / Q000196:embryology* / Q000235:genetics*; D013997:Time Factors; D015533:Transcriptional Activation / Q000187:drug effects / Q000235:genetics
chemical_list: D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D056920:Nuclear Receptor Coactivator 1