Figure 6.

ATL is required for ER network formation in a fractionated system. (A) Interphase cytosol, light membranes, and an energy regenerating system were mixed and incubated for 30 min with buffer, 2 µM of the cytoplasmic fragment of X. laevis ATL2 (cytATL), or 2 µM of mutant fragment (cytATL(R232Q)). The membranes were stained with octadecyl rhodamine and visualized by confocal microscopy. (B) As in A, but the mitotic state was generated by addition of cyclin BΔ90. (C) Interphase ER network formation with DiOC₁₈ prelabeled light membranes was performed at different GTP concentrations for 15 min at room temperature. Bars, 20 µm.