Version 2 2021-09-10, 19:36Version 2 2021-09-10, 19:36
Version 1 2021-09-10, 12:35Version 1 2021-09-10, 12:35
journal contribution
posted on 2021-09-10, 19:36authored byWim Dejonghe, Aditya S. Vaidya, Simon E. Alfred, Sean R. Cutler
Several small-molecule
perturbagens of the plant endomembrane system
are known, but few selectively disrupt endoplasmic reticulum (ER)
structure and function. We conducted a microscopy-based screen for
small-molecule disruptors of ER structure and discovered eroonazole,
a 1,2-4-triazole that induces extensive ER vesiculation in Arabidopsis seedlings. To identify eroonazole targets, we
synthesized a clickable photoaffinity derivative and used it for whole-seedling
labeling experiments. These reveal that the probe labels multiple
oleosins, plant membrane proteins that stabilize ER-derived lipid
droplets. Oleosin labeling is absent in an oleosin1234 quadruple mutant and reduced using an inactive analog. Cellular
analyses of the ER in the quadruple mutant demonstrate that oleosins
are required for normal ER structure during seed germination and suggest
that perturbation of oleosin function by eroonazole underlies its
effects on seedling ER structure.