Figure 2.

Smooth tubule formation in tER is NEM sensitive. LDM were incubated for 60 min (as in Figure 1b) and in the additional presence of 2 mM NEM for 180 min. (a) Membrane networks essentially devoid of interconnecting smooth tubules were observed; scale bar represents 200 nm. Structures labeled rm correspond to parallel rough ER membranes. (a inset) Arrowheads point to ribosomes; scale bar represents 100 nm. (b) Quantitation of the effect of NEM. The amount of membrane networks with rough ER membranes and distinct smooth ER tubules were counted for control incubations minus NEM (tER) as well as for NEM-treated membranes (tER 60′ + NEM).