In this study we have generated a EYFP targeted to the mitochondrial intermembrane space (MIMS-EYFP) to determine for the first time the pH within this compartment. The fragment encoding HAI-tagged EYFP was fused with the C-terminus of glycerol-phosphate dehydrogenase, an integral protein of the inner mitochondrial membrane. Human ECV304 cells transiently transfected with MIMS-EYFP showed the typical mitochondrial network, co-localized with MitoTracker Red. Following the calibration procedure, an estimation of the pH value in the intermembrane space was obtained. This value (6.88 ± 0.09) was significantly lower than that determined in the cytosol after transfection with a cytosolic EYFP (7.59 ± 0.01). Further, the pH of the mitochondrial matrix, determined with a EYFP targeted to this subcompartment, was 0.9 pH units higher than that in the intermembrane space. In conclusion, MIMS-EYFP represents a novel powerful tool to monitor pH changes in the mitochondrial intermembrane space of live cells.
pH difference across the outer mitochondrial membrane measured with a green fluorescent protein mutant / A. M.PORCELLI; A. GHELLI; C. ZANNA; P. PINTON; R. RIZZUTO; M.RUGOLO. - In: BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS. - ISSN 0006-291X. - STAMPA. - 326:(2005), pp. 779-804. [10.1016/j.bbrc.2004.11.105]
pH difference across the outer mitochondrial membrane measured with a green fluorescent protein mutant
PORCELLI, ANNA MARIA;GHELLI, ANNA MARIA;ZANNA, CLAUDIA;RUGOLO, MICHELA
2005
Abstract
In this study we have generated a EYFP targeted to the mitochondrial intermembrane space (MIMS-EYFP) to determine for the first time the pH within this compartment. The fragment encoding HAI-tagged EYFP was fused with the C-terminus of glycerol-phosphate dehydrogenase, an integral protein of the inner mitochondrial membrane. Human ECV304 cells transiently transfected with MIMS-EYFP showed the typical mitochondrial network, co-localized with MitoTracker Red. Following the calibration procedure, an estimation of the pH value in the intermembrane space was obtained. This value (6.88 ± 0.09) was significantly lower than that determined in the cytosol after transfection with a cytosolic EYFP (7.59 ± 0.01). Further, the pH of the mitochondrial matrix, determined with a EYFP targeted to this subcompartment, was 0.9 pH units higher than that in the intermembrane space. In conclusion, MIMS-EYFP represents a novel powerful tool to monitor pH changes in the mitochondrial intermembrane space of live cells.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.