To investigate what causes the ER-to-Golgi movement of GFP-VSVP,
COS cells were incubated for 15 min in iced culture medium containing
nocodazole (1 mg/ml), washed free of nocodazole and incubated at
32 oC in regular growth medium. For comparison
purposes, the previous figure and video are presented in the left-hand
frame, the nocodazole figure and video in the center frame.
Consider
both videos, noting the great difference in time elapsed, and
answer the questions posed in the right-hand frame. The video
images were captured every 4 min. The movie lasts about 9
sec, is run at 4 frames per sec, and the movement of the fluorescent
protein is greatly speeded up about 240-fold.
[You can learn more about these phenomena and the following
experiments by consulting the video essay by Presley, et al. 1998
Mol Biol. Cell 9:1617-1626. PMID9658158]
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