Characterization of Drosophila and Caenorhabditis elegans NXF-like-factors, putative homologs of mammalian NXF.
The basic helix-loop-helix/Per-Arnt-Sim (bHLH-PAS) homology protein family is an important class of transcriptional regulators that are involved in a wide variety of biological processes. In a previous study, we characterized a novel bHLH-PAS factor 'NXF' as a new member of the mammalian bHLH-PAS family. If model animals have ortholog genes for NXF, they might have advantages for characterization of its function and regulation in vivo. Here we document cDNA cloning and characterization of putative NXF homolog genes (for NXF-like-factors) in Drosophila and C. elegans. Some conservation of the exon-intron gene architecture was noted in the bHLH-PAS domains among NXF-like-factors and human NXF. The NXF-like-factors selectively interacted with an Arnt ortholog in vitro assay. Moreover, they selectively associated with the mammalian NXF:Arnt2 binding element in the presence of the Arnt ortholog, and synergistically activated a mammalian NXF:Arnt-responsive promoter. These data strongly suggest that the Drosophila and C. elegans NXF-like-factors reported here are homologs of mammalian NXF. Further elucidation of whether they are true orthologs with the same function in vivo is now necessary.
Ooe
Norihisa
N
Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., Konohana-ku, Osaka 554-8558, Japan. ooe@sc.sumitomo-chem.co.jp
Saito
Koichi
K
Oeda
Kenji
K
Nakatuka
Iwao
I
Kaneko
Hideo
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D029721:Drosophila Proteins / Q000235:genetics*; D006242:Haptoglobins; D006801:Humans; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D015533:Transcriptional Activation
D051792:Basic Helix-Loop-Helix Proteins; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D029721:Drosophila Proteins; D006242:Haptoglobins; C485359:HP protein, human; C481603:NPAS4 protein, human