Abstract
ER body, which is derived from endoplasmic reticulum, is a spindle-shaped structure (~10 μm long and ~1 μm wide). ER bodies are easily detected in the transgenic Arabidopsis expressing the ER-localized green fluorescent protein (GFP). A major component of ER bodies is β-glucosidase (PYK10). To clarify the molecular mechanism underlying formation of the unique shaped ER bodies, we applied forward genetic approach. We isolated an Arabidopsis mutant that had abnormally elongated ER bodies. The mutation was found in the PYK10 molecule, in which Cys-5 was replaced with Tyr at the N-terminal region. This suggests that a major component of ER bodies is responsible for determination or modulation of ER body shape. We succeeded in induction of ER bodies in Arabidopsis suspension cultured cells. This experimental system will make it possible to investigate the formation process of ER bodies.
