Mps1 with all leucines substituted in pNES1 reside in the cytoplasm. (A) Schematic of Mps1 mutant with mutated pNES1 (Mps1mutNES1). The lysines in red were mutated to alanines (upper panel). The sequencing result of the mutated pNES1 (middle and lower panel). (B, C) The subcellular distribution of YFP fused Mps1 and Mps1mutNES1 in presence of LMB and DMSO. The quantitative result of fusion distribution was generated as in Figure 2C. (D) Western blot of 293 T cells shows the expression of YFPMps1 and YFPMps1mutNES1 in SW480 cell lines.