Fig. 4: PDI competitively binding to misfolded proteins with GRP78 to activate UPRER. | Cell Death & Differentiation

Fig. 4: PDI competitively binding to misfolded proteins with GRP78 to activate UPRER.

From: A novel HIF-2α targeted inhibitor suppresses hypoxia-induced breast cancer stemness via SOD2-mtROS-PDI/GPR78-UPRER axis

Fig. 4

A The location of mtROS in mitochondria and ER was observed by confocal microscope. Scale bar, 10 μm. B The protein expression of PDI was detected in HIF-2α OE MCF7 cells and HIF-2α KD MCF7 MS cells, under 1% O2. C The enzyme activities of PDI in HIF-2α OE MCF7 cells and HIF-2α KD MCF7 MS cells were measured, under 1% O2. D The level and location of mtROS and PDI were measured in HIF-2α KD MCF7 MS cells were detected by immunofluorescence microscopy, under 1% O2. Scale bar, 5 μm. E The protein expression and enzyme activity of PDI were measured in HIF-2α KD MCF7 MS cells cultured with mitoTEMPOL (100 µM), under 1% O2. F The direct interaction of GRP78 and PDI in MCF7 MS cells was determined by co-immunoprecipitation (co-IP). G The level of misfolded protein was detected in HIF-2α KD MCF7 MS cells by confocal microscope. Scale bar, 10 μm. H The expression levels of GRP78, PDI and misfolded proteins were detected in the GRP78-overexpressing (GRP78 OE), PDI-overexpressing (PDI OE) MCF7 MS cells by immunofluorescence microscopy, under 1% O2. Scale bar, 20 μm. I The combination and dissociation of GRP78 and PERK was confirmed by co-immunoprecipitation (co-IP) in HIF-2α KD MCF7 MS cells cultured with 16F16 (100 µM), under 1% O2. J–L The protein expressions of PDI and GRP78, cell viability rate and self-renewal ability were detected in HIF-2α KD MCF7 MS cells cultured with 16F16 (100 µM), under 1% O2. Scale bar, 250 μm.

Back to article page