Abstract
In the cortical region of cell, tubular structures of endoplasmic reticulum (ER) are arranged into meshwork. The contraction of tubular ER in the cortical region has been shown to be suppressed by inhibitors for actin cytoskeleton. We found that tubular structures (ER-tube) were formed in vitro from the vesicles of ER prepared from tobacco cultured cells BY-2, in which GFP-labeled ER (GFP-ER) was expressed, by the addition of GTP, but not by ATP or GDP. On the other hand, the formation of ER-tube was induced in the presence of myosin inhibitor, 2,3-butanedione monoxime, or depolymerizing drugs for actin filaments. However, the SH blockers, such as N-ethylmaleimide or biotin-maleimide, suppressed the formation of ER-tube. Similar phenomenon had been shown in the ER fraction prepared from Xenopus eggs. However, several differences in the formation of ER-tube in vitro were found between plant and animal materials. We will also discuss these points.
