Table 1. Summary of fits for GFP-GR (GR) and all eight H1⁰-GFP constructs.

	FRAP parameters			Calculated parameters
	Fast state	Slow state		Bound fraction		Free fraction	Bound/free
	D or Deff (μm2/s)	ta (s)	tr (s)	Slow	Fast
GR	2.5±0.3	8.5±1.4	3.6±0.5	30±4%	0%	70±4%	0.4±0.2
3KO	6.1±0.2	—	—	—	0%	100%	0
S2	5.3±0.5	5.6±2.2	1.1±0.3	16±6%	11±7%	73±9%	0.4±0.2
S1	3.7±0.2	—	—	—	39±4%	61±4%	0.7±0.1
S1S2	3.3±0.3	8.8±2.7	1.7±0.4	16±5%	39±5%	45±5%	1.2±0.3
C	0.96±0.1	17±2.4	6.1±0.7	26±4%	61±3%	13±1%	6.9±0.7
S2C	0.52±0.1	14±2.2	5.7±0.8	29±4%	64±4%	7±1%	14±2
S1C	0.40±0.1	17±3.6	8.5±1.0	33±5%	62±5%	5±1%	20±3
WT	0.033±0.003	270±60	100±18	28±6%	71±5%	0.4±0.1%	230±30
The spatio-temporal FRAP data were fit for each construct generating estimated parameters for a diffusion coefficient (either pure diffusion D or effective diffusion Deff), and an association time (ta) and residence time (tr). All values are averages of at least 10 fits to single-cell FRAP data taken over 3 or more days. From these, the fraction of molecules bound in fast (effective diffusive) and slow binding states can be calculated using Supplementary equations (S.1) and (S.2). For GR and 3K0, the diffusion coefficient is interpreted as pure diffusion (D). For the other H10-GFP constructs, the diffusion coefficients are always less than the 3K0 pure diffusion coefficient (even after correcting for differences in mass, as described in the Supplementary data), so they are interpreted as effective diffusion. As the 3K0 mutant exhibited negligible binding (see Supplementary data), the binding of the other H10-GFP constructs can be attributed to S1, S2, and C binding regions.