DNA binding and transactivating properties of the paired and homeobox protein Pax4

Biochem Biophys Res Commun. 1999 Jun 16;259(3):510-8. doi: 10.1006/bbrc.1999.0809.


Transcription factors Pax-4 and Pax-6 are known to be key regulators of pancreatic cell differentiation and development. We report on the cloning of a mouse Pax-4 gene, which contains 10 exons, spanning a 4. 7-kbp region. The gene-targeting experiments revealed that Pax-4 and Pax-6 cannot substitute for each other in tissue with overlapping expression of both genes. We identified DNA-binding specificities of Pax-4 paired domain and paired-type homeodomain. Despite the different Pax-4 amino acid residues in positions responsible for Pax-6 paired-domain specificity, the DNA-binding specificities of Pax-4 and Pax-6 are similar. The Pax-4 homeodomain was shown to preferentially dimerize on DNA sequences consisting of an inverted TAAT motif, separated by 4-nucleotide spacing. The Pax-4 transactivation domain was localized within its C-terminal region, which transactivated GAL-based reporter 2.5-fold less than the C-terminal region of Pax-6. We believe that Pax-4 can act as a Pax-6 "repressor," due to the competition for binding sites and lower transactivation potential of Pax-4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cells, Cultured
  • Cloning, Molecular
  • DNA-Binding Proteins / physiology*
  • Dose-Response Relationship, Drug
  • Exons
  • Eye Proteins
  • Homeodomain Proteins / physiology*
  • Humans
  • Introns
  • Kidney / metabolism
  • Luciferases / metabolism
  • Mice
  • Molecular Sequence Data
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Repressor Proteins
  • Sequence Homology, Amino Acid
  • Transcription Factors / physiology*
  • Transcriptional Activation / physiology*


  • DNA-Binding Proteins
  • Eye Proteins
  • Homeodomain Proteins
  • PAX4 protein, human
  • PAX6 Transcription Factor
  • PAX6 protein, human
  • Paired Box Transcription Factors
  • Pax4 protein, mouse
  • Pax6 protein, mouse
  • Repressor Proteins
  • Transcription Factors
  • Luciferases

Associated data

  • GENBANK/AF142321
  • GENBANK/AF145233