A novel type of DNA-binding protein interacts with a conserved sequence in an early nodulin ENOD12 promoter

Henning Christiansen, Anette C. Hansen, Irma Vijn, Niels Pallisgaard, Knud Larsen, Wei Cai Yang, Ton Bisseling, Kjeld A. Marcker, Erik Jensen*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

Abstract

The pea genes PsENOD12A and PsENOD12B are expressed in the root hairs shortly after infection with the nitrogen-fixing bacterium Rhizobium leguminosarum by visiae or after application of purified Nod factors. A 199 bp promoter fragment of the PsENOD12B gene contains sufficient information for Nod factor-induced tissue specific expression. We have isolated a Vicia sativa cDNA encoding a 1641 amino acid protein, ENBP1, that interacts with the 199 bp ENOD12 promoter. Two different DNA-binding domains were identified in ENBP1. A domain containing six AT-hooks interacts specifically with an AT- rich sequence located between positions -95 and -77 in the PsENOD12B promoter. A second domain in ENBP1 is a cysteine-rich region that binds to the ENOD12 promoter in a sequence non-specific but metal-dependent way. ENBP1 is expressed in the same cell types as ENOD12. However, additional expression is observed in the nodule parenchyma and meristem. The presence of three small overlapping ORFs in the 5'-untranslated region of the ENBP1 cDNA indicates that ENBP1 expression might be regulated at the translational level. The interaction of ENBP1 with a conserved AT-rich element within the ENOD12 promoter and the presence of the ENBP1 transcript in cells expressing ENOD12 strongly suggest that ENBP1 is a transcription factor involve in the regulation of ENOD12. Finally, the C-terminal of ENBP1 shows strong homology to a protein from rat that is specifically expressed in testis tissue.

Original languageEnglish
JournalPlant Molecular Biology
Volume32
Issue number5
Pages (from-to)809-821
Number of pages13
ISSN0167-4412
DOIs
Publication statusPublished - 1996
Externally publishedYes

Keywords

  • AT hook
  • cis element
  • ENOD12
  • nodulin
  • root nodule
  • trans acting factor

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