Current Genetics

, Volume 34, Issue 6, pp 449–458

In vivo mitochondrial DNA-protein interactions in sea urchin eggs and embryos

Authors

  • Marina Roberti
    • Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, via Orabona 4A, I-70125, Bari, Italy e-mail: csmmal05@area.ba.cnr.it Tel.: +39-80-5443378 Fax: +39-80-5443317
  • Paola Loguercio Polosa
    • Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, via Orabona 4A, I-70125, Bari, Italy e-mail: csmmal05@area.ba.cnr.it Tel.: +39-80-5443378 Fax: +39-80-5443317
  • Clara Musicco
    • Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, via Orabona 4A, I-70125, Bari, Italy e-mail: csmmal05@area.ba.cnr.it Tel.: +39-80-5443378 Fax: +39-80-5443317
  • Francesco Milella
    • Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, via Orabona 4A, I-70125, Bari, Italy e-mail: csmmal05@area.ba.cnr.it Tel.: +39-80-5443378 Fax: +39-80-5443317
  • Sohail A. Qureshi
    • Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
  • Maria N. Gadaleta
    • Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, via Orabona 4A, I-70125, Bari, Italy e-mail: csmmal05@area.ba.cnr.it Tel.: +39-80-5443378 Fax: +39-80-5443317
  • Howard T. Jacobs
    • Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
  • P. Cantatore
    • Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, via Orabona 4A, I-70125, Bari, Italy e-mail: csmmal05@area.ba.cnr.it Tel.: +39-80-5443378 Fax: +39-80-5443317
ORIGINAL PAPER

DOI: 10.1007/s002940050419

Cite this article as:
Roberti, M., Loguercio Polosa, P., Musicco, C. et al. Curr Genet (1999) 34: 449. doi:10.1007/s002940050419

Abstract

Footprinting studies with the purine-modifying agent dimethyl sulphate were performed in Paracentrotus lividus eggs and embryos to analyze in vivo the interactions between protein and mitochondrial DNA. Footprinting in the small non-coding region and at the boundary between the ND5 and ND6 genes revealed two strong contact sites corresponding with the in vitro binding sequences of mitochondrial D-loop-Binding Protein (mtDBP). The analysis of the pause region of mtDNA replication showed a strong footprint corresponding with the binding site of the mitochondrial Pause region-Binding Protein-2 (mtPBP-2), but only a very weak signal at the binding site of the mitochondrial Pause region-Binding Protein-1 (mtPBP-1), which in vitro binds DNA with high efficiency. In vitro and in vivo analysis of the 3′ end-region of the two rRNA genes showed no significant protein-DNA interactions, suggesting that, in contrast to mammals, the 3′ ends of sea urchin mitochondrial rRNAs are not generated by a protein-dependent transcription termination event. These and other data support a model in which expression of mitochondrial genes in sea urchins is regulated post-transcriptionally. Footprinting at the five AT-rich consensus regions allowed the detection of a binding site in the non-coding region for an as-yet unidentified protein, mtAT-1BP. The occupancy of this site appears to be developmentally regulated, being detectable in the pluteus larval stage, but not in unfertilized eggs.

Key words Sea urchinmtDNADMS footprintingDNA-binding proteins
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© Springer-Verlag Berlin Heidelberg 1999