Figure 9.

Dominant-negative atlastin proteins prominently disrupt ER morphology. HeLa cells expressing Myc-tagged atlastin-1, -2 or -3 (upper panels) exhibit a typical reticular ER morphology, as revealed by co-labeling with VSVG-GFP at 40°C. However, expression of Myc-tagged SPG3A atlastin-1 mutant R217Q and the equivalent mutations atlastin-2^R244Q or atlastin-3^R187Q result in a more tubular, elongated ER morphology with much less branching (middle panels). This profound effect on ER morphology was also seen to the same, if not greater, extent upon expression of Myc-tagged dominant-negative mutations atlastin-1^K80A, atlastin-2^K107A, or atlastin-3^K47A (bottom panels). Bars, 10 µm.