Disease relevance of MYB2

• These observations indicate that Atmyb2 is responsive to dehydration at the transcriptional level [1].
• A fusion protein that included ATMYB2 was expressed in Escherichia coli, and it bound specifically to oligonucleotides that contained a consensus MYB recognition sequence (TAACTG), such as is found in the simian virus 40 enhancer and the maize bronze-1 promoter [1].
• We show that AtMYB2 is induced by hypoxia with kinetics compatible with a role in the regulation of ADH1 [2].

High impact information on MYB2

• Arabidopsis AtMYC2 (bHLH) and AtMYB2 (MYB) function as transcriptional activators in abscisic acid signaling [3].
• These results indicate that both AtMYC2 and AtMYB2 proteins function as transcriptional activators in ABA-inducible gene expression under drought stress in plants [3].
• A null rop10 mutant exhibits enhanced responses to ABA in seed germination, root elongation, and stomatal closure assays and in the induction of expression of the transcription factor MYB2, but it shows wild-type levels of ABA and normal responses to other hormones [4].
• A gene (Atmyb2) corresponding to the Atmyb2 cDNA was also cloned and its nucleotide sequence was determined [1].
• An Arabidopsis cDNA (Atmyb2) that contains a sequence that encodes a transcription factor, which is a homolog of MYB, was cloned from a cDNA library prepared from dehydrated Arabidopsis rosette plants [1].

Biological context of MYB2

• Similar experiments with a distantly related MYB gene (MYB2) showed that its product cannot functionally substitute for WER or GL1 [5].
• A transcriptional activation domain of ATMYB2, a drought-inducible Arabidopsis Myb-related protein [6].
• ATMYB2 activated the transcription of a reporter gene from the MYB-binding site in a sequence-specific manner [6].
• Further insights into the phylogeny of Arabidopsis (Brassicaceae) from nuclear Atmyb2 flanking sequence [7].

Anatomical context of MYB2

• Trans-activation activity of ATMYB2, a drought-inducible Myb-related protein in Arabidopsis thaliana, was analyzed using a transient assay of Arabidopsis leaf protoplasts [6].

Associations of MYB2 with chemical compounds

• Here, we show that transgenic plants overexpressing AtMYC2 and/or AtMYB2 cDNAs have higher sensitivity to ABA [3].
• The putative protein (ATMYB2) encoded by Atmyb2 has 274 amino acids, a molecular mass of 32 kD, and a putative DNA binding domain that shows considerable homology to plant MYB-related proteins, such as maize C1 [1].
• Overexpression of Gm-CaM4 in Arabidopsis up-regulates the transcription rate of AtMYB2-regulated genes, including the proline-synthesizing enzyme P5CS1 (Delta1-pyrroline-5-carboxylate synthetase-1), which confers salt tolerance by facilitating proline accumulation [8].

Physical interactions of MYB2

• The transcription factor AtMYB2 binds to two sequence motifs in the promoter of the Arabidopsis ADH1 gene [2].

Other interactions of MYB2

• These results indicate that ATMYB2 acts as a transcriptional activator and that the C-terminal acidic region of ATMYB2 can function as a transcriptional activation domain [6].
• When driven by a constitutive promoter, AtMYB2 is able to transactivate ADH1 expression in transient assays in both Arabidopsis and Nicotiana plumbaginifolia protoplasts, and in particle bombardment of Pisum sativum leaves [2].

Analytical, diagnostic and therapeutic context of MYB2

• Microarray analysis of the transgenic plants overexpressing both AtMYC2 and AtMYB2 cDNAs revealed that several ABA-inducible genes also are upregulated in the transgenic plants [3].
• RNA gel blot analysis showed that the Atmyb2 mRNA was induced by dehydration and disappeared upon rehydration [1].

References