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Change of a conserved amino acid in the MYC 2 and MYC 3 transcription factors leads to release of JAZ repression and increased activity
Author(s) -
Goossens Jonas,
Swinnen Gwen,
Vanden Bossche Robin,
Pauwels Laurens,
Goossens Alain
Publication year - 2015
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13398
Subject(s) - jasmonate , transcription factor , mutant , psychological repression , amino acid , chemistry , microbiology and biotechnology , gene , biology , arabidopsis , biochemistry , gene expression
Summary The bHLH transcription factor MYC2, together with its paralogues MYC3 and MYC4, is a master regulator of the response to the jasmonate (JA) hormone in A rabidopsis ( A rabidopsis thaliana ). In the absence of JA, JASMONATE ZIM (JAZ) proteins interact with the MYC proteins to block their activity. Understanding of the mechanism and specificity of this interaction is key to unravel JA signalling. We generated mutant MYC proteins and assessed their activity and the specificity of their interaction with the 12 A rabidopsis JAZ proteins. We show that the D94N mutation present in the atr2D allele of MYC 3 abolishes the interaction between MYC 3 and most JAZ proteins. The same effect is observed when the corresponding conserved Asp (D105) was mutated in MYC 2. Accordingly, MYC 2 D105N activated target genes in the presence of JAZ proteins, in contrast to wild‐type MYC 2. JAZ 1 and JAZ 10 were the only JAZ proteins still showing interaction with the mutant MYC proteins, due to a second MYC interaction domain, besides the classical Jas domain. Our results visualize the divergence among JAZ proteins in their interaction with MYC proteins. Ultimately, the transferability of the Asp‐to‐Asn amino acid change might facilitate the design of hyperactive transcription factors for plant engineering.