The AtMYB12 activation domain maps to a short C-terminal region of the transcription factor

Abstract

Abstract:The Arabidopsis thaliana R2R3-MYB transcription factor MYB12 is a light-inducible, flavonolspecific activator of flavonoid biosynthesis. The transactivation activity of the AtMYB12 protein was analyzed using a C-terminal deletion series in a transient A. thaliana protoplast assay with the goal of mapping the activation domain (AD). Although the deletion of the last 46 C-terminal amino acids did not affect the activation capacity, the deletion of the last 98 amino acids almost totally abolished transactivation of two different target promoters. A domain swap experiment using the yeast GAL4 DNA-binding domain revealed that the region from positions 282 to 328 of AtMYB12 was sufficient for transactivation. In contrast to the R2R3-MYB ADs known thus far, that of AtMYB12 is not located at the rearmost C-terminal end of the protein. The AtMYB12 AD is conserved in other experimentally proven R2R3-MYB flavonol regulators from different species.

Functional Characterization of BoaMYB51s as Central Regulators of Indole Glucosinolate Biosynthesis in Brassica oleracea var. alboglabra Bailey

“…Here, we identified the TAD of BoaMYB51, which is also located in the C-terminal region, by using yeast two-hybrid system and tobacco transient assay (Figures 8A,B ). According to previous reports, the TAD of a TF often contains acidic, glutamine-rich, or proline-rich stretches of amino acids (Stracke et al, 2017 ). The TAD of BoaMYB51 defined in this study is enriched in acidic amino acids, but proline-rich or glutamine-rich amino acid stretches were not identified, which is in good accordance with the features of the TADs of above-mentioned R2R3-MYB TFs.…”

“…From studies by Goff et al ( 1992 ), the TAD of the ZmC1 is located in a carboxy-terminal acidic region. Moreover, the C-terminal acidic region of AtMYB2 and AtMYB12 was found to be able to activate transcription (Urao et al, 1996 ; Stracke et al, 2017 ). Here, we identified the TAD of BoaMYB51, which is also located in the C-terminal region, by using yeast two-hybrid system and tobacco transient assay (Figures 8A,B ).…”

Functional characterisation of banana (Musa spp.) 2-oxoglutarate-dependent dioxygenases involved in flavonoid biosynthesis

“…The resulting PCR products were recombined into pDONR™/Zeo (Invitrogen) with BP clonase (Invitrogen) resulting in Entry plasmids, which were sequenced by Sanger technology (Sanger et al, 1977) on 3730XL sequencers using BigDye terminator v3.1 chemistry (Thermo Fisher). Entry plasmids for AtF3H, AtFLS1 and AtMYB12 were available from previous studies (Preuss et al, 2009; Stracke et al, 2017), PcFNSI was amplified on a plasmid from a previous study (Martens et al, 2003). The full-length CDSs were introduced from the Entry plasmids into the inducible E. coli expression vector pDEST17 (Invitrogen) and the binary expression vector pLEELA (Jakoby et al, 2004) using GATEWAY LR-reaction (Invitrogen).…”

Intrinsic Disorder in Plant Transcription Factor Systems: Functional Implications

“…Several of the conserved regions overlap with functional sites. For example, the MYB sub-group 12 SLiM, (L/F)LN(K/R)(V/L)A, mediates interactions with the bHLH TFs MYC3, and MYC4 [ 117 ] (see below) ( Figure 1 C) ( Table 1 ), and for MYB12, a member of sub-group 7 and a light-induced activator of flavonoid biosynthesis [ 130 ], the conserved region maps to a short C-terminal IDR [ 27 , 116 ].…”