Disease relevance of ABH1

• Moreover, expression of a 35SAtPP2CA cDNA fusion in abh1 partially suppresses abh1 hypersensitivity, and the data further suggest that additional mechanisms contribute to ABA hypersensitivity of abh1 [1].

High impact information on ABH1

• Thus, ABH1 represents a modulator of ABA signaling proposed to function by transcript alteration of early ABA signaling elements [2].
• An mRNA cap binding protein, ABH1, modulates early abscisic acid signal transduction in Arabidopsis [2].
• Making use of the ABA-hypersensitive hyl1 mutant of Arabidopsis, we show that the ABA signal is transmitted to the transcriptional apparatus through mitogen-activated protein kinase signaling [3].
• The results suggest a role for nuclear transport in ABA signal transduction, and the possible roles of SAD2 in relation to that of SAD1 and ABH1 are discussed [4].
• In this work we have generated ABA-hypersensitive drought-avoidant mutants by simultaneous inactivation of two negative regulators of ABA signaling, i.e. the protein phosphatases type 2C (PP2Cs) ABA-INSENSITIVE1 (ABI1) and HYPERSENSITIVE TO ABA1 (HAB1) [5].

Biological context of ABH1

• Whole-plant growth phenotypes of abh1 are described and properties of ABH1 in guard cells are further analyzed [6].
• Both proteins AtCBP20 and AtCBP80 are encoded by single-copy genes in the A. thaliana genome [7].
• The AtCBP20 gene is located on chromosome V, and the AtCBP80 gene is encoded by chromosome II [7].
• We show here that down-regulation of AtPP2CA in abh1 is not due to impaired RNA splicing of AtPP2CA pre-mRNA [1].

Anatomical context of ABH1

• Complemented abh1 lines expressing a green fluorescent protein-ABH1 fusion protein demonstrate that ABH1 mainly localizes in guard cell nuclei [6].
• The second subunit of the Arabidopsis cap-binding complex, AtCBP80, shows 28% identity and 50% similarity to its homologue from HeLa cells [7].

Associations of ABH1 with chemical compounds

• Molecular analysis showed that the mutations are caused by lesions in the gene encoding the large subunit of the nuclear mRNA cap-binding protein, ABH1 (ABA hypersensitive1) [8].

Regulatory relationships of ABH1

• Lesions in the mRNA cap-binding gene ABA HYPERSENSITIVE 1 suppress FRIGIDA-mediated delayed flowering in Arabidopsis [8].

Other interactions of ABH1

• Here, we show that the dimeric ABH1 and AtCBP20 subunits are ubiquitously expressed [6].
• Localization, ion channel regulation, and genetic interactions during abscisic acid signaling of the nuclear mRNA cap-binding protein, ABH1 [6].
• Analysis of ABA hypersensitive germination2 revealed the pivotal functions of PARN in stress response in Arabidopsis [9].
• The ABA-hypersensitive phenotype of hab1-1 seeds together with the reduced ABA sensitivity of 35S:HAB1 plants are consistent with a role of HAB1 as a negative regulator of ABA signalling [10].

Analytical, diagnostic and therapeutic context of ABH1

• DNA chip analyses show that only a few transcripts are down-regulated in abh1, several of which are implicated in ABA signaling [2].

References