Transcriptional activity and developmental expression of liver X receptor (lxr) in zebrafish.
Mammalian liver-X-receptors (LXRs) are transcription factors activated by oxysterols. They play an essential role in lipid and glucose metabolism. We have cloned the open reading frame of zebrafish lxr and describe its genomic organization. Zebrafish lxr encodes a 50-kDa protein with high sequence similarity to mammalian LXRalpha. In transfection assays, the encoded protein showed transcriptional activity in response to LXR-ligands. Treatment of adult zebrafish with the synthetic LXR ligand, GW3965, induced expression of genes involved in hepatic cholesterol and lipid pathways. Using qPCR and in situ hybridization, we found ubiquitous expression of lxr mRNA during the first 24 hr of development, followed by more restricted expression, particularly to the liver at 3dpf and the liver and intestine at 4dpf. In adult fish, all examined organs expressed lxr. In addition to a metabolic role of lxr, the temporal expression pattern suggests a developmental role in, e.g., the liver and CNS.
Archer
Amena
A
Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Huddinge, Sweden. amena.archer@biosci.ki.se
Lauter
Gilbert
G
Hauptmann
Giselbert
G
Mode
Agneta
A
Gustafsson
Jan-Ake
JA
D000595:Amino Acid Sequence; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D000071518:Liver X Receptors; D008969:Molecular Sequence Data; D057093:Orphan Nuclear Receptors; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014018:Tissue Distribution; D014158:Transcription, Genetic; D015027:Zebrafish / Q000033:anatomy & histology / Q000196:embryology / Q000235:genetics* / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D000071518:Liver X Receptors; C000605213:NR1H3 protein, human; D057093:Orphan Nuclear Receptors; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear; D029961:Zebrafish Proteins