Disease relevance of ERA1

• Deletion of the Arabidopsis farnesyltransferase gene ERA1 or application of farnesyltransferase inhibitors resulted in ABA hypersensitivity of guard cell anion-channel activation and of stomatal closing [1].

High impact information on ERA1

• A collection of mutations, designated era, in Arabidopsis thaliana that confer an enhanced response to exogenous ABA includes mutations in the Era1 gene, which encodes the beta subunit of a protein farnesyl transferase [2].
• These data indicate that the ERA1 farnesyltransferase targets a negative regulator of ABA signaling that acts between the points of ABA perception and the activation of plasma membrane calcium influx channels [3].
• Complementation of era1-2 with LeFTB, the tomato gene for the beta subunit of FTase, restored a normal phenotype and confirmed that the lesion is in AtFTB alone [4].
• Cloning of the Arabidopsis WIGGUM gene identifies a role for farnesylation in meristem development [5].
• DNA sequencing revealed that WIGGUM is identical to ERA1 (enhanced response to abscisic acid), a previously identified farnesyltransferase beta-subunit gene of Arabidopsis [5].

Biological context of ERA1

• To test the effectiveness of tailoring farnesylation in a crop plant, transgenic Brassica napus carrying an ERA1 antisense construct driven by a drought-inducible rd29A promoter was examined [6].
• Based on reporter gene constructs, the upstream regulation of ABI3 by ERA1 occurs at least partially at the level of transcription, suggesting that this lipid modification is required to attenuate ABI3 expression [7].
• We propose that WIGGUM plays a role in restricting cell division relative to cellular differentiation in specific regions of the apical and floral meristems [8].
• We describe the phenotypic effects of mutations in WIGGUM, a gene required for control of cell proliferation in the floral and apical meristem of Arabidopsis thaliana. wiggum flowers contain more organs, especially sepals and petals, than found in wild-type flowers [8].
• Proceeding from these results three direct questions can be posed for present (LDEF-1) and future (ERA-1, D-2) experiments in space: What is the influence of cosmic radiation on cytogenetic repair and ontogenetic restitution processes [9]?

Associations of ERA1 with chemical compounds

• Previous genetic studies have implicated the involvement of the beta-subunit of Arabidopsis farnesyltransferase (ERA1) in the regulation of ABA sensing and drought tolerance [6].
• Related to this, loss-of-function abi3 alleles show reduced lateral root responsiveness in the presence of auxin and an auxin transport inhibitor, and era1 mutants have increased numbers of lateral roots [7].

Other interactions of ERA1

• These results suggest the possibility that genes identified through ABA responsive germination screens such as ERA1 and ABI3 have functions in auxin action in Arabidopsis [7].
• Genetic studies suggest that WIGGUM acts on a similar process but in a separate pathway than the CLAVATA1 and CLAVATA3 genes in meristem size regulation, and reveal interactions with other genes affecting meristem structure and identity [8].

Analytical, diagnostic and therapeutic context of ERA1

• Using in situ hybridization, we examined the expression of ERA1 throughout development and found it to be nearly ubiquitous [5].

References