title: elt-1, an embryonically expressed Caenorhabditis elegans gene homologous to the GATA transcription factor family.
abstract: The short, asymmetrical DNA sequence to which the vertebrate GATA family of transcription factors binds is present in some Caenorhabditis elegans gene regulatory regions: it is required for activation of the vitellogenin genes and is also found just 5' of the TATA boxes of tra-2 and the msp genes. In vertebrates GATA-1 is specific to erythroid lineages, whereas GATA-2 and GATA-3 are present in multiple tissues. In an effort to identify the trans-acting factors that may recognize this sequence element in C. elegans, we used a degenerate oligonucleotide to clone a C. elegans homolog to this gene. We call this gene elt-1 (erythrocytelike transcription factor). It is single copy and specifies a 1.75-kb mRNA that is present predominantly, if not exclusively, in embryos. The region of elt-1 encoding two zinc fingers is remarkably similar to the DNA-binding domain of the vertebrate GATA-binding proteins. However, outside of the DNA-binding domains the amino acid sequences are quite divergent. Nevertheless, introns are located at identical or nearly identical positions in elt-1 and the mouse GATA-1 gene. In addition, elt-1 mRNA is trans-spliced to the 22-base untranslated leader, SL1. The DNA upstream of the elt-1 TATA box contains eight copies of the GATA recognition sequence within the first 300 bp, suggesting that elt-1 may be autogenously regulated. Our results suggest that the specialized role of GATA-1 in erythroid gene expression was derived after separation of the nematodes and the line that led to the vertebrates, since C. elegans lacks an erythroid lineage.
authors.affiliation: Program in Molecular, Cellular and Developmental Biology, Indiana University, Bloomington 47405.
authors.forename: J
authors.initials: J
authors.lastname: Spieth
authors.forename: Y H
authors.initials: YH
authors.lastname: Shim
authors.forename: K
authors.initials: K
authors.lastname: Lea
authors.forename: R
authors.initials: R
authors.lastname: Conrad
authors.forename: T
authors.initials: T
authors.lastname: Blumenthal
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002107:Caenorhabditis / Q000196:embryology / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D015534:Trans-Activators / Q000235:genetics*; D014819:Vitellogenins / Q000235:genetics
chemical_list: D015534:Trans-Activators; D014819:Vitellogenins; D004247:DNA