I-POU: a POU-domain protein that inhibits neuron-specific gene activation

Nature. 1991 Apr 18;350(6319):577-84. doi: 10.1038/350577a0.


A novel, structurally distinct POU-domain protein has been identified that inhibits activation by another positive POU-domain regulator of neuron-specific transcription units. Two Drosophila POU-domain proteins, I-POU and Cf1-a, are coexpressed in overlapping subsets of neurons during development. Because I-POU lacks two basic residues in the N terminus of its homeodomain, it cannot bind DNA, but it does form a stable heterodimeric complex with Cf1-a, preventing Cf1-a from binding to DNA recognition elements and from transactivating the dopa-decarboxylase gene. The inhibition by I-POU provides a potential strategy by which the activation of genes in development is controlled by a homeodomain-containing protein that does not bind DNA.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • DNA-Binding Proteins / genetics*
  • Dopa Decarboxylase / genetics
  • Drosophila / genetics
  • Drosophila / growth & development
  • Drosophila Proteins*
  • Gene Expression Regulation*
  • Genes, Homeobox
  • Molecular Sequence Data
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Neurons / physiology*
  • POU Domain Factors
  • RNA, Messenger / genetics
  • Sequence Homology, Nucleic Acid
  • Transcription Factors*
  • Transcription, Genetic
  • Transcriptional Activation


  • DNA-Binding Proteins
  • Drosophila Proteins
  • Nerve Tissue Proteins
  • POU Domain Factors
  • RNA, Messenger
  • Transcription Factors
  • acj6 protein, Drosophila
  • Dopa Decarboxylase

Associated data

  • GENBANK/X57450
  • GENBANK/X57451
  • GENBANK/X57452
  • GENBANK/X57453
  • GENBANK/X57454
  • GENBANK/X57455
  • GENBANK/X57688
  • GENBANK/X57689
  • GENBANK/X58435
  • GENBANK/X58436