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Deletion of a C–terminal intrinsically disordered region of WRINKLED 1 affects its stability and enhances oil accumulation in Arabidopsis
Author(s) -
Ma Wei,
Kong Que,
Grix Michael,
Mantyla Jenny J.,
Yang Yang,
Benning Christoph,
Ohlrogge John B.
Publication year - 2015
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12933
Subject(s) - arabidopsis , phosphorylation , transactivation , complementation , transcription factor , bimolecular fluorescence complementation , biochemistry , biology , microbiology and biotechnology , chemistry , gene , mutant
Summary WRINKLED 1 ( WRI 1) is a key transcription factor governing plant oil biosynthesis. We characterized three intrinsically disordered regions ( IDR s) in Arabidopsis WRI 1, and found that one C–terminal IDR of At WRI 1 ( IDR 3) affects the stability of At WRI 1. Analysis by bimolecular fluorescence complementation and yeast‐two‐hybrid assays indicated that the IDR 3 domain does not determine WRI 1 stability by interacting with BTB / POZ ‐ MATH proteins connecting At WRI 1 with CULLIN 3‐based E3 ligases. Analysis of the WRI 1 sequence revealed that a putative PEST motif (proteolytic signal) is located at the C–terminal region of At WRI 1 IDR 3 . We also show that a 91 amino acid domain at the C–terminus of At WRI 1 without the PEST motif is sufficient for transactivation. We found that removal of the PEST motif or mutations in putative phosphorylation sites increased the stability of At WRI 1, and led to increased oil biosynthesis when these constructs were transiently expressed in tobacco leaves. Oil content was also increased in the seeds of stable transgenic wri1–1 plants expressing At WRI 1 with mutations in the IDR 3 ‐PEST motif. Taken together, our data suggest that intrinsic disorder of AtWRI1 IDR3 may facilitate exposure of the PEST motif to protein kinases. Thus, phosphorylation of the PEST motif in the At WRI 1 IDR 3 domain may affect At WRI 1‐mediated plant oil biosynthesis. The results obtained here suggest a means to increase accumulation of oils in plant tissues through WRI 1 engineering.