Quantitation of the distribution and flux of myosin-II during cytokinesis

Table 1 Quantitation of myosin-II distribution during cytokinesis : Comparison with minimal force requirements.

	Interphase	Spherical	Cylindrical	Dumbbell
Cell volume, μm^{3 a}	620	620	690	720
Volume of cell cortex, μm^{3 a}	120	120	130	160
Volume of furrow, μm^{3 a}	-	-	40	20
Total wild type myosin-II, % total [μM]	100 [3.4]	100 [3.4]	100 [3.4]	100 [3.4]
Cytoplasm^b	77 ± 2 [3.2]	79 ± 2 [3.4]	79 ± 2 [3.4]	73 ± 2 [3.2]
Total cortex^b	23 ± 0.3 [4.0]	21 ± 0.5 [3.6]	21 ± 0.5 [3.8]	27 ± 0.5 [4.2]
Furrow cortex^b	-	-	8.4 ± 0.2 [5.0]	5.3 ± 0.4 [6.4]
Total 3 × Ala myosin-II, % total [μM]	100 [3.4]	100 [3.4]	100 [3.4]	100 [3.4]
Cytoplasm^b	74 ± 2 [3.2]	77 ± 2 [3.2]	76 ± 8 [3.2]	70 ± 4 [3.0]
Total cortex^b	26 ± 0.8 [4.6]	23 ± 0.5 [4.0]	24 ± 1 [4.4]	30 ± 0.1 [4.6]
Furrow cortex^b	-	-	13 ± 1 [7.6]	16 ± 1 [18]
Minimal force requirements, nN^c	-	-	7.2	2.7
% of total myosin-II required for this amount of force^d	-	-	12	4.5

^a These quantities were calculated based upon the geometry and dimensions of the cell. ^b These quantities were calculated from the empirically determined concentrations derived from the ratio imaging analysis. ^c These quantities were calculated based upon the dimensions of the cell. ^d These quantities were calculate by considering the amount of minimal required force, the physical properties of myosin-II and the amount of myosin-II in the cell.

ISSN: 2661-8850