Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Medicine and Health Sciences
Fluorescence Imaging Detection Of Nanodomain Redox Signaling Events At Organellar Contacts, David M. Booth, Péter Várnai, Suresh K Joseph, György Hajnóczky
Fluorescence Imaging Detection Of Nanodomain Redox Signaling Events At Organellar Contacts, David M. Booth, Péter Várnai, Suresh K Joseph, György Hajnóczky
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
This protocol describes how to visualize, detect, and analyze redox signals (oxidative bursts) at the ER-mitochondrial interface. It uses drug-inducible crosslinking to target the genetically encoded glutathione redox sensor Grx1roGFP2 to organellar contact sites to measure local redox changes associated with transient depolarizations of the mitochondrial membrane potential (flickers). The strategy allows imaging of the oxidized to reduced glutathione ratio (GSSG:GSH) in subcellular regions below the diffraction limit with good temporal resolution and minimum phototoxicity. Moreover, the strategy also applies to diverse parameters including pH, H2O2, and Ca2+.
Dysregulation Of Ryr Calcium Channel Causes The Onset Of Mitochondrial Retrograde Signaling, Anindya Roy Chowdhury, Satish Srinivasan, György Csordás, György Hajnóczky, Narayan G Avadhani
Dysregulation Of Ryr Calcium Channel Causes The Onset Of Mitochondrial Retrograde Signaling, Anindya Roy Chowdhury, Satish Srinivasan, György Csordás, György Hajnóczky, Narayan G Avadhani
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
This study shows that multiple modes of mitochondrial stress generated by partial mtDNA depletion or cytochrome c oxidase disruption cause ryanodine receptor channel (RyR) dysregulation, which instigates the release of Ca2+ in the cytoplasm of C2C12 myoblasts and HCT116 carcinoma cells. We also observed a reciprocal downregulation of IP3R channel activity and reduced mitochondrial uptake of Ca2+. Ryanodine, an RyR antagonist, abrogated the mitochondrial stress-mediated increase in [Ca2+]c and the entire downstream signaling cascades of mitochondrial retrograde signaling. Interestingly, ryanodine also inhibited mitochondrial stress-induced invasive behavior in mtDNA-depleted C2C12 cells and HCT116 carcinoma cells. In addition, co-immunoprecipitation shows reduced FKBP12 …