The zinc finger network of plants.

The zinc finger domain enables different proteins to interact with or bind DNA, RNA, or other proteins, and is present in the proteomes of many different organisms. Proteins containing zinc finger domain(s) were found to play important roles in eukaryotic cells regulating different signal transduction pathways and controlling processes, such as development and programmed cell death. There are many types of zinc finger proteins, classified according to the number and order of the Cys and His residues that bind the Zinc ion. Among these, the C2H2-type zinc finger proteins, with 176 members in Arabidopsis thaliana, constitute one of the largest families of transcriptional regulators in plants. They are mostly plant-specific and contain a conserved QALGGH sequence within their zinc finger domain. Recent studies revealed that C2H2 zinc finger proteins could function as key transcriptional repressors involved in the defense and acclimation response of plants to different environmental stress conditions. Here we highlight recent functional characterization studies of different C2H2 proteins in Arabidopsis, and suggest that many of these proteins function as part of a large regulatory network that senses and responds to different environmental stimuli.