Table 1.

UPR stress decreases BiP mobility

Construct	DTT	Tm	n	D (μm2/s)a
HepG2 cells
ER-GFP	Untreated		18	6.6 ± 0.7
	1 h		13	6.7 ± 0.5
ER-RFP		Untreated	10	9.1 ± 0.6
		4 h	12	9.3 ± 1.2
BiP-GFP	Untreated		26	0.60 ± 0.06
	1 h		13	0.33 ± 0.05b
MDCK cells
ER-RFP		Untreated	12	5.1 ± 0.4
		4h	13	8.1 ± 0.6b
BiP-GFP		Untreated	12	0.32 ± 0.03
		4 h	13	0.16 ± 0.02b
Cos7 cells
ER-RFP	Untreated		15	10.4 ± 0.5
	1 h		10	10.0 ± 0.9
BiP-GFP	Untreated		15	1.1 ± 0.1
	1 h		10	0.6 ± 0.1 (p = 0.015)
ER-RFP		Untreated	14	9.1 ± 0.5
		4 h	13	10.9 ± 0.5
BiP-GFP		Untreated	14	1.2 ± 0.2
		4 h	13	0.7 ± 0.1 (p = 0.0299)
U2-OS cells
ER-RFP		Untreated	15	6.6 ± 0.5
		4 h	13	7.7 ± 1.1
BiP-GFP		Untreated	15	0.37 ± 0.03
		4 h	13	0.17 ± 0.02b

HepG2, MDCK, or U2-OS cells were transfected for 20–36 h with BiP-GFP, ER-GFP or ER-RFP treated with 5 mM DTT for 1 h or 5 μg/ml Tm for 4 h (10 mM DTT for 1 h for Cos7), and subjected to FRAP analysis.

^a Values are mean ± SEM.

^b p ≤ 0.01; two-tailed Student's t test comparing treated with untreated cells.