Cis-acting elements of the sea urchin histone H2A modulator bind transcriptional factors.
Functional tests, performed by microinjection into Xenopus laevis oocytes, show that a DNA fragment containing the modulator of the early histone H2A gene of Paracentrotus lividus enhances transcription of a reporter gene when located, in the physiological orientation, upstream of the tk basal promoter. Gel retardation and DNase I footprinting assays further reveal that the H2A modulator contains at least two binding sites [upstream sequence elements 1 and 2 (USE 1 and USE 2)] for nuclear factors extracted from sea urchin embryos, which actively transcribe the early histone gene set. Interestingly, USE 1 is highly homologous to a cis-acting element previously identified in the H2A modulator of Psammechinus miliaris [Grosschedl, R., Mächler, M., Rohrer, U. & Birnstiel, M. L. (1983) Nucleic Acids Res. 11, 8123-8136]. Finally, a cloned oligonucleotide containing the USE 1 sequence competes efficiently in Xenopus oocytes with the H2A modulator to prevent enhancement of transcription of the reporter gene. From these results, we conclude that USE 1 and perhaps USE 2 in the H2A modulator are upstream transcriptional elements that are recognized by trans-acting factors common to Xenopus and sea urchin.
Dipartimento di Biologia Cellulare e dello Sviluppo, Palermo, Italy.
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Spinelli
D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D005260:Female; D005796:Genes; D006657:Histones / Q000235:genetics*; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D010957:Plasmids; D015183:Restriction Mapping; D012617:Sea Urchins / Q000196:embryology; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014982:Xenopus laevis
D006657:Histones; D014157:Transcription Factors; D004247:DNA