High impact information on AHBP-1B

• We show that TGA2 and NPR1 are recruited to PR-1 independently of each other and of SA treatment [1].
• To elucidate the biological functions of these three TGA transcription factors, we analyzed single and combined deletion knockout mutants of TGA2, TGA5, and TGA6 for SA-induced PR gene expression and pathogen resistance [2].
• Because leaf transfection assays indicate that TGA3 activates transcription, as noted previously for TGA2, these two TGA factors are predicted to make positive contributions to the expression of this target gene [3].
• Knockout analysis of Arabidopsis transcription factors TGA2, TGA5, and TGA6 reveals their redundant and essential roles in systemic acquired resistance [2].
• These genetic data clearly demonstrate that TGA2 is a SA-responsive and NPR1-dependent transcription activator [4].

Biological context of AHBP-1B

• In this study, we expressed a truncated form of TGA2 in Arabidopsis and found that the resulting transgenic lines displayed phenotypes similar to those of npr1 mutants [4].
• In vivo interaction between NPR1 and transcription factor TGA2 leads to salicylic acid-mediated gene activation in Arabidopsis [4].
• However, low stringency Southern blot analyses with homologous and heterologous probes suggest that there is a multigene family of TGA1a-related genes present in Arabidopsis, of which TGA1, TGA2 and TGA3 are members [5].
• Interestingly, 15 of the putative binding sites for TGA2 lie outside the presumptive promoter regions [6].

Anatomical context of AHBP-1B

• Using bimolecular fluorescence complementation analysis, we show that NPR3 interacts with TGA2 in the nucleus of onion epidermal cells and Arabidopsis mesophyll protoplasts [7].

Associations of AHBP-1B with chemical compounds

• Protein-DNA complexes resulting from the formaldehyde fixation of leaves of plants 2 h after exposure to 1 mm salicylic acid (SA) were immunoprecipitated using antibodies against the TGA2 transcription factor [6].

Physical interactions of AHBP-1B

• Coupled with observations that the DNA binding activity of TGA factors is deregulated in npr1 plants, the results suggest that NPR1-mediated DNA binding of TGA2 is critical for activation of defense genes [8].

Other interactions of AHBP-1B

• The binding specificity and tissue-specific expression pattern of TGA2 (AHBP-1b), an Arabidopsis bZIP transcription factor have been determined [9].

Analytical, diagnostic and therapeutic context of AHBP-1B

• Genomic Southern blot analysis confirmed that TGA2 is a member of the gene family [9].
• Furthermore, a gel mobility shift assay showed that the purified transcription factor protein, AHBP-1b, binds specifically to an SA-responsive promoter element of the A. thaliana PR-1 gene [10].

References