1. MMAP is required for spindle dynamics regulation.
MMAP is required for spindle dynamics regulation. (A and B) Immunofluorescence (A) showing that MMAP is required for the normal function of the spindle. (Scale bar, 5 μm.) The relative intensity of α-tubulin and KIF2A on the metaphase spindle (n ≥ 30 cells for each sample) was quantified and plotted in B. The error bars show the SD. (C) A FLIP assay showing that MMAP promotes MT turnover. HeLa cells stably expressing GFP–α-tubulin were transfected with lenti-shRNA viruses. GFP fluorescence intensity was acquired every 0.76 s while a photobleaching laser was focused to a diffraction-limited spot in the cytoplasm away from the spindle. Sixteen half-spindles from 16 metaphase cells were quantified, and fluorescence signals for each half-spindle were normalized to their intensity at 0 s. The means and SEs are shown in the plots. P value is from two-tailed t test. (D) A graph showing the intensity of the MTs and KIF2A on the spindle in the complementation assay. MMAP−/− HCT116 cells were transfected with wild-type MMAP, the MMAP short isoform (S), or the 6A or 6D MMAP mutants 48 h before immunofluorescence. Vec, empty vector. Thirty metaphase cells were quantified in each sample. The data represent the mean values, and the error bars represent SD. The typical images are shown in SI Appendix, Fig. S14.
Ran Xu et al. PNAS 2018;115:43:E10079-E10088
©2018 by National Academy of Sciences