Table 2.

GFP-NM-IIAΔIQ2 displays faster half-time of recovery in live cells

Construct	Half-time (s)	Immobile fraction (%)
GFP-NMHC-IIA (n = 44)	125 ± 74	41 ± 21
GFP-NMHC-IIAΔtailpiece (n = 49)	130 ± 100	50 ± 22*
GFP-NMHC-IIAΔIQ2 (n = 33)	90 ± 41*	65 ± 12*

FRAP was performed on GFP-myosin assembled at the lamella of actively spreading cells transfected with the indicated construct. Average half-time of recoveries and immobile fractions are shown ± SD. The immobile fraction is GFP-myosin that did not exchange with the monomer pool during the course of the experiment and is therefore a metric for over assembly. Both Δtailpiece and ΔIQ2 mutants significantly over-assemble compared with wild type, indicated by their increased immobile fractions (Δtailpiece p = 0.04; ΔIQ2 p = 0.0000007). Surprisingly, the ΔIQ mutant had a faster half-time of recovery compared with wild type (p = 0.015). The Δtailpiece myosin recovered with a half time indistinguishable from wild type. Asterisks indicate significantly different values. Significance determined by a two-tailed t test.