Disease relevance of EIN3

• In contrast with what has been previously found in EIN3- and TEIL-overexpressing Arabidopsis plants, transgenic tobacco seedlings expressing the VR-EIL genes under the control of cauliflower mosaic virus 35S promoter did not exhibit a constitutive triple response [1].

High impact information on EIN3

• Here, we identify two Arabidopsis F box proteins called EBF1 and EBF2 that interact physically with EIN3/EIL transcription factors [2].
• Plants overexpressing either F box gene display ethylene insensitivity and destabilization of EIN3 protein [3].
• Ethylene signal transduction initiates with ethylene binding at a family of ethylene receptors and terminates in a transcription cascade involving the EIN3/EIL and ERF families of plant-specific transcription factors [2].
• The Arabidopsis EIN3 protein is a key transcription factor mediating ethylene-regulated gene expression and morphological responses [3].
• Plants containing mutations in either gene show enhanced ethylene response by stabilizing EIN3, whereas efb1 efb2 double mutants show constitutive ethylene phenotypes [3].

Biological context of EIN3

• Overexpression of EIN3 or EIL1 in wild-type or ethylene-insensitive2 plants conferred constitutive ethylene phenotypes, indicating their sufficiency for activation of the pathway in the absence of ethylene [4].
• In this study, we show that EIN3 and EILs comprise a family of novel sequence-specific DNA-binding proteins that regulate gene expression by binding directly to a primary ethylene response element (PERE) related to the tomato E4-element [5].
• The EIN3/EIL proteins bind to the promoter regions of the downstream genes and regulate their expression [6].
• To gain a better understanding of the ethylene signal transduction pathway in rice, six EIN3-like genes (designated OsEIL1-6) were identified [7].
• To examine the mechanism of EIN3-mediated gene expression by ethylene, the expression patterns of ethylene-inducible genes by ethylene were monitored in Col-0 and ethylene signaling mutants [8].

Associations of EIN3 with chemical compounds

• Differential regulation of EIN3 stability by glucose and ethylene signalling in plants [9].
• Several fundamental elements of the pathway have been described: a receptor with homology to bacterial two-component histidine kinases (ETR1), elements of a MAP kinase cascade (CTR1) and a putative transcription factor (EIN3) [10].

Physical interactions of EIN3

• EBF1 and -2 interact directly with ethylene insensitive 3 (EIN3), a transcriptional regulator important for ethylene signaling [11].
• EIN3 can specifically bind SID2 promoter sequence in vitro and in vivo [12].

Regulatory relationships of EIN3

• OsEIL1, a rice homolog of the Arabidopsis EIN3 regulates the ethylene response as a positive component [7].
• These results reveal that a ubiquitin/proteasome pathway negatively regulates ethylene responses by targeting EIN3 for degradation, and pinpoint EIN3 regulation as the key step in the response to ethylene [3].

Other interactions of EIN3

• EIN3 BINDING F-BOX1 (EBF1) and EBF2 were recently shown to function in ethylene perception by regulating EIN3/EIL turnover [13].
• A major gap is represented by the mysterious plant protein EIN2 that genetically works downstream of CTR1 and upstream of the key transcription factor EIN3 [14].
• In the absence of ethylene, EIN3 and possibly other EIL proteins are targeted for ubiquitination and subsequent degradation by Cullin 1-based E3 complexes containing EBF1 and 2 [13].
• Here, we identify the major DBD of an EIN3/EIL protein, Arabidopsis thaliana EIL3, containing a key mutational site for DNA binding and signaling (ein3-3 site), and determine its solution structure by NMR spectroscopy [6].
• Moreover, we identified an immediate target of EIN3, ETHYLENE-RESPONSE-FACTOR1 (ERF1), which contains this element in its promoter [5].

References