Researchers at the John Innes Centre and partners at the Chinese Academy of Sciences have identified a molecular switch that establishes differential cell growth and organ shape.
DAR2 cleavage of TMK1-EGFP relocates it from the plasma membrane to the nucleus of Arabidopsis root protoplasts. (A–H) Confocal images of dar2-1 root protoplasts transformed with TMK1-EGFP, histone HT2B-mCherry, and cleavage mutants with or without DAR2. HT2B-mCherry marks the nucleus. Colocation of TMK1-EGFP and HT2B-mCherry shows as yellow fluorescence. (Scale bars: 5 µm.) (I) Ratios of nuclear-localized/total protoplast EGFP in different TMK1-EGFP cleavage mutants. n = 20 protoplasts from each of three independent experiments. All were compared to TMK-EGFP levels without 3HA-DAR2, and significant differences are indicated as *P < 0.05. Credit: Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2205757119 The growth regulator auxin promotes cell growth through a surface protein called Transmembrane Kinase 1 (TMK1). At the cell surface TMK1 modulates cell wall properties that facilitate cell growth. But TMK1 also signals an…