Similar DNA recognition properties of alternatively spliced Drosophila POU factors

Proc Natl Acad Sci U S A. 1996 Dec 24;93(26):15097-101. doi: 10.1073/pnas.93.26.15097.

Abstract

The POU-IV or "Brn-3" class of POU-domain transcription factors is represented in Drosophila by I-POU and twin-of-I-POU, alternative splice products of the I-POU gene. I-POU has been previously reported to inhibit DNA binding by the POU-III class factor drifter/Cf1a via the formation of heterodimeric complexes. Here we report that expression of the I-POU/tI-POU message is maximal late in the embryonic phase of Drosophila development, and I-POU is the preferred splice variant. Although I-POU lacks two basic amino acid residues in the POU-homeodomain found in tI-POU and Brn-3.0, these three POU-IV class proteins exhibit very similar DNA-binding specificity. In contrast to previously published reports, the results presented here show no effect of I-POU on DNA binding by drifter, and no evidence for I-POU/drifter dimerization. These results suggest that the I-POU/tI-POU gene products function by transcriptional mechanisms similar to those of the homologous POU-IV class factors expressed in other species, not by unique inhibitory mechanism.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Antennapedia Homeodomain Protein
  • Base Sequence
  • Binding Sites
  • Conserved Sequence
  • DNA / chemistry
  • DNA / metabolism*
  • DNA Primers
  • DNA-Binding Proteins*
  • Drosophila
  • Drosophila Proteins
  • Exons
  • Homeodomain Proteins / biosynthesis
  • Homeodomain Proteins / chemistry*
  • Homeodomain Proteins / metabolism*
  • Host Cell Factor C1
  • Insect Hormones / chemistry
  • Introns
  • Mammals
  • Molecular Sequence Data
  • Nuclear Proteins*
  • Octamer Transcription Factor-1
  • Oligodeoxyribonucleotides
  • Protein Structure, Secondary
  • Sequence Homology, Amino Acid
  • Transcription Factors / biosynthesis
  • Transcription Factors / chemistry*
  • Transcription Factors / metabolism*

Substances

  • Antennapedia Homeodomain Protein
  • Antp protein, Drosophila
  • DNA Primers
  • DNA-Binding Proteins
  • Drosophila Proteins
  • En protein, Drosophila
  • Homeodomain Proteins
  • Host Cell Factor C1
  • Insect Hormones
  • Nuclear Proteins
  • Octamer Transcription Factor-1
  • Oligodeoxyribonucleotides
  • Transcription Factors
  • DNA