Disease relevance of PAP1

• The proanthocyanidin (PA) content was increased in seeds of pap1-D mutant of Arabidopsis thaliana, in which the expression of endogenous PAP1 gene encoding a Myb-like transcription factor was induced by activation-tagging with enhancer sequences derived from cauliflower mosaic virus 35S promoter [1].
• Interaction of the tobacco mosaic virus replicase protein with the Aux/IAA protein PAP1/IAA26 is associated with disease development [2].

High impact information on PAP1

• Here, we report a comprehensive analysis of the metabolome and transcriptome of Arabidopsis thaliana over-expressing the PAP1 gene encoding an MYB transcription factor, for the identification of novel gene functions involved in flavonoid biosynthesis [3].
• This combined analysis revealed the specific accumulation of cyanidin and quercetin derivatives, and identified eight novel anthocyanins from an array of putative 1800 metabolites in PAP1 over-expressing plants [3].
• When coupled with constitutive expression of PAP1, a positive regulator of anthocyanin biosynthesis, TT2 expression in Arabidopsis led to accumulation of proanthocyanidins, but only in a subset of cells in which the BANYULS promoter is naturally expressed [4].
• In this study, the helicase domain of the Tobacco mosaic virus (TMV) 126- and/or 183-kDa replicase protein(s) was found to interact with the Arabidopsis Aux/IAA protein PAP1 (also named IAA26), a putative regulator of auxin response genes involved in plant development [2].
• A total of four quantitative trait loci for SIAA were identified in this way [5].

Biological context of PAP1

• The enhancement by oxidative stress and fermentable carbon sources did not depend on the presence of Pap1 [6].

Associations of PAP1 with chemical compounds

• Two MYB transcription factor genes, PAP1 and PAP2, were identified as senescence-associated genes that are induced by glucose [7].
• In contrast, the PA contents decreased in seeds of transgenic plants transformed with a PAP1 cDNA or with a PAP1 chimeric repressor, although the amount of soluble anthocyanins increased in seeds of transgenic plants over-expressing PAP1 cDNA [1].
• Sucrose-specific induction of anthocyanin biosynthesis in Arabidopsis requires the MYB75/PAP1 gene [5].
• The PDI mRNA levels were increased in both Pap1-positive and Pap1-negative cells treated with glycerol [6].

Other interactions of PAP1

• The existing Landsberg erecta/Cvi recombinant inbred line population was used in a quantitative trait loci analysis for Suc-induced anthocyanin accumulation (SIAA) [5].

Analytical, diagnostic and therapeutic context of PAP1

• The transcriptome analysis of 22,810 genes on a DNA microarray revealed the induction of 38 genes by ectopic PAP1 over-expression [3].
• Sequence analysis showed that the Cvi and C24 accessions harbor mutations both inside and downstream of the DNA-binding domain of the MYB75/PAP1 protein, which most likely result in loss of activity [5].

References