O-glycosylation of the transcription factor SPATULA promotes style development in Arabidopsis

Nat Plants. 2024 Feb;10(2):283-299. doi: 10.1038/s41477-023-01617-4. Epub 2024 Jan 26.

Abstract

O-linked β-N-acetylglucosamine (O-GlcNAc) and O-fucose are two sugar-based post-translational modifications whose mechanistic role in plant signalling and transcriptional regulation is still largely unknown. Here we investigated how two O-glycosyltransferase enzymes of Arabidopsis thaliana, SPINDLY (SPY) and SECRET AGENT (SEC), promote the activity of the basic helix-loop-helix transcription factor SPATULA (SPT) during morphogenesis of the plant female reproductive organ apex, the style. SPY and SEC modify amino-terminal residues of SPT in vivo and in vitro by attaching O-fucose and O-GlcNAc, respectively. This post-translational regulation does not impact SPT homo- and heterodimerization events, although it enhances the affinity of SPT for the kinase PINOID gene locus and its transcriptional repression. Our findings offer a mechanistic example of the effect of O-GlcNAc and O-fucose on the activity of a plant transcription factor and reveal previously unrecognized roles for SEC and SPY in orchestrating style elongation and shape.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis Proteins* / metabolism
  • Arabidopsis* / physiology
  • Fucose
  • Glycosylation
  • Plants / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Arabidopsis Proteins
  • Fucose
  • Transcription Factors
  • SPT protein, Arabidopsis