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  • Arabidopsis   PROTODERMAL FACTOR2 binds lysophosphatidylcholines and transcriptionally regulates phospholipid metabolism
Title: Arabidopsis   PROTODERMAL FACTOR2 binds lysophosphatidylcholines and transcriptionally regulates phospholipid metabolism
Summary Plant homeodomain leucine zipper IV (HD‐Zip IV) transcription factors (TFs) contain an evolutionarily conserved steroidogenic acute regulatory protein (StAR)‐related lipid transfer (START) domain. While the START domain is required for TF activity, its presumed role as a lipid sensor is not clear.Here we used tandem affinity purification fromArabidopsiscell cultures to demonstrate that PROTODERMAL FACTOR2 (PDF2), a representative member that controls epidermal differentiation, recruits lysophosphatidylcholines (LysoPCs) in a START‐dependent manner. Microscale thermophoresis assays confirmed that a missense mutation in a predicted ligand contact site reduces lysophospholipid binding.We additionally found that PDF2 acts as a transcriptional regulator of phospholipid‐ and phosphate (Pi) starvation‐related genes and binds to a palindromic octamer with consensus to a Pi response element. Phospholipid homeostasis and elongation growth were altered inpdf2mutants according to Pi availability. Cycloheximide chase experiments revealed a role for START in maintaining protein levels, and Pi starvation resulted in enhanced protein destabilization, suggesting a mechanism by which lipid binding controls TF activity.We propose that the START domain serves as a molecular sensor for membrane phospholipid status in the epidermis. Our data provide insights toward understanding how the lipid metabolome integrates Pi availability with gene expression.  more » « less
Award ID(s):
2226270
PAR ID:
10520048
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
Wiley-Blackwell Publishing
Date Published:
Journal Name:
New Phytologist
ISSN:
0028-646X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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