FIGURE 1:

Overexpression of 3xAsp in WT cells reduced growth rate. (A) Diagram of WT myosin II and 3xAsp myosin II. (B) GFP-WT myosin II accumulates at the furrow. Scale bar, 10 μm. (C) Myosin II distribution in myoII::GFP-3xAsp;mCh-WT myosin II was altered by expression of 3xAsp myosin II. GFP-3xAsp and mCherry-WT myosin II colocalized at the cleavage furrow in dividing cells but with an aberrant distribution. Scale bar, 10 μm. (D) WT cells expressing GFP-3xAsp (WT::3xAsp) did not show mechanosensitive myosin II accumulation in response to micropipette aspiration (white arrow). The background-corrected fluorescence intensity ratio of the cortex inside the micropipette (I_p) and the opposite cortex (I_o) was measured and used to determine whether the myosin II undergoes mechanosensitive accumulation (Effler et al., 2006). Scale bar, 10 μm. (E) Suspension culture growth for WT control and WT::3xAsp cells. Average growth rate is 0.067 ± 0.008 h⁻¹ for WT cells (n = 11) and 0.032 ± 0.009 h⁻¹ for WT::3xAsp cells (n = 11; p value is on the graph). (F) Western analysis of WT and WT::GFP-3xAsp (where 3xAsp is integrated randomly in the genome) showed that 3xAsp is 40% and WT endogenous myosin II is 60% of the total myosin II in these cells.