Figure 1.

GFP human p60 is as effective as X. laevis p60. (A) Example time series of Dylight649 microtubules (MTs) being severed by X. laevis katanin-p60 (Xl-p60). The severing assays were 10 min long with a frame taken every 5 s. The times series depicts a frame every 10 s. The scale bar is 5 μm. By the end of the movie, the microtubules are completely destroyed. The first frame is bright and out of focus due to the enzyme being flowed into the chamber. (B) Example two-color imaging time series of severing assays with GFP-Hu-p60. (i) Time series of Dylight649 microtubules in a severing assay with GFP-Hu-p60. Microtubules are completely destroyed by the end of the assay. The first frame is bright and out of focus due to the enzyme being flowed into the chamber. (ii) Time series of the same assay in (i) showing GFP-Hu-p60 binding along the microtubules. GFP-Hu-p60 was added during the first frame in the time series and, within two frames, is completely decorating the microtubules. (iii) A merge of (i) and (ii). Red is the Dylight649 microtubules and cyan is GFP-Hu-p60. The severing assays were 10 minutes long with a frame taken every 5 s. The times series depicts a frame every 10 s. The scale bars are 5 μm. (C) Quantification of fraction of microtubule polymer remaining over the course of severing assay for microtubules with Xl-p60 (orange diamonds, N = 55, fit to Eq. 2), microtubules with GFP-Hu-p60 (green diamonds, N = 73, fit to Eq. 1), and microtubules alone (pink diamonds, N = 56, fit to Eq. 3). Fit parameters are in Table S1. Error bars represent mean ± SE. (D) The characteristic decay times from the fits in (C). (i) Decay times depicted over the same, long scale. (ii) Decay times depicted over same short scale such that the data within the dashed rectangle of (i) are discernable.