You have purified a protein, MT1, that binds only to GTP-bound tubulin. You proceed to fuse MT1 to GFP and find that the fusion of GFP to MT1 does not disrupt MT1 function in any way (good news!). You use a different dye to label the microtubules in red so that you can visualize MT1-GFP and the microtubules at the same time. (Note that the red dye does not affect the microtubule’s properties.)

A. If you were to polymerize some red-labeled microtubules in a dish, would you expect MT1-GFP to be associated with one or both ends of a microtubule, with the middle of the microtubule, or be evenly distributed throughout the microtubule? Explain.

B. If you were to take time-lapse images in which you visualize only MT1- GFP (and not microtubules), what would you expect to see? Describe what you think would happen to MT1-GFP over time with respect to its localization inside of this cell.