The Arabidopsis AtDi19 gene family encodes a novel type of Cys2/His2 zinc-finger protein implicated in ABA-independent dehydration, high-salinity stress and light signaling pathways

Plant Mol Biol. 2006 May;61(1-2):13-30. doi: 10.1007/s11103-005-5798-7.

Abstract

The AtDi19 (drought-induced) gene family encodes seven hydrophilic proteins that contain two atypical Cys2/His2 (C2H2) zinc finger-like domains that are evolutionarily well-conserved within angiosperms suggesting a conserved and important function. Five of the seven Arabidopsis AtDi19-related:DsRed2 fusion proteins exhibited speckled patterns of localization within the nucleus as shown by transient expression analysis in Arabidopsis protoplasts. In contrast, AtDi19-2:DsRed2 was present in the nucleus and cytoplasm, whereas AtDi19-4:DsRed2 was localized to the nuclear periphery. mRNA expression studies showed that AtDi19 genes are ubiquitously expressed in Arabidopsis tissues, although some differences were observed. In seedlings, RT-PCR analyses showed that AtDi19-1 and AtDi19-3 steady-state transcript amounts were rapidly induced by dehydration, whereas transcript amounts for AtDi19-2 and AtDi19-4 increased in response to high-salt stress. In addition, the mRNA abundance of all the AtDi19-related gene family members was not regulated by ABA. These data, taken together, suggest that several AtDi19-related gene family members may function in ABA-independent, dehydration and salinity stress signaling pathways. However, they may also be regulated by other abiotic stimuli. AtDi19-7, for example, has been implicated in regulating light signaling and responses. Finally, we show that most AtDi19-related proteins are phosphorylated in vitro by calcium-dependent protein kinases suggesting that this post-translational modification may be important for regulating the function of this novel protein family.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / metabolism
  • Amino Acid Sequence
  • Arabidopsis / cytology
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / physiology
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics*
  • Carrier Proteins / physiology
  • Conserved Sequence
  • Dehydration
  • Evolution, Molecular
  • Gene Expression Regulation, Plant
  • Light
  • Molecular Sequence Data
  • Multigene Family* / physiology
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / physiology
  • Oligonucleotide Array Sequence Analysis
  • Protein Processing, Post-Translational
  • Protein Structure, Tertiary
  • Protoplasts / metabolism
  • RNA, Messenger / metabolism
  • Sequence Alignment
  • Signal Transduction
  • Sodium Chloride / metabolism
  • Zinc Fingers

Substances

  • Arabidopsis Proteins
  • Carrier Proteins
  • Di19 protein, Arabidopsis
  • Nuclear Proteins
  • RNA, Messenger
  • Sodium Chloride
  • Abscisic Acid