Mutually exclusive interaction of the CCAAT-binding factor and of a displacement protein with overlapping sequences of a histone gene promoter

Cell. 1987 Jul 31;50(3):347-59. doi: 10.1016/0092-8674(87)90489-2.


The sperm histone H2B-1 gene of the sea urchin Psammechinus miliaris contains two octamer sequences (ATTTGCAT) and two CCAAT motifs upstream of its TATA box. The CCAAT-binding factors present in nuclear extracts from testis and from blastula and gastrula embryos are indistinguishable by mobility shift and methylation interference analysis. However, there is a testis-specific octamer-binding factor in addition to the ubiquitous form. In DNAase I protection experiments, the CCAAT-binding factor of only the testis extract is able to interact with the sperm H2B promoter. In the two embryonic extracts a novel factor binds with high affinity to sequences overlapping the proximal CCAAT element, thus preventing the DNA interaction of the CCAAT-binding factor in the embryo where the sperm H2B gene is not expressed. This CCAAT displacement protein may therefore act as a repressor of sperm H2B gene transcription.

MeSH terms

  • Base Sequence
  • Embryo, Nonmammalian
  • Gene Expression Regulation
  • Histones / genetics*
  • Male
  • Organ Specificity
  • Promoter Regions, Genetic*
  • Protein Binding
  • Sea Urchins
  • Spermatozoa / ultrastructure
  • Testis / ultrastructure
  • Transcription, Genetic


  • Histones