Format

Send to

Choose Destination
Front Cell Neurosci. 2019 Oct 4;13:449. doi: 10.3389/fncel.2019.00449. eCollection 2019.

Development and Application of Sub-Mitochondrial Targeted Ca2 + Biosensors.

Author information

1
Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria.
2
Energy Metabolism Laboratory, Institute of Translational Medicine, D-HEST, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.
3
Department of Internal Medicine, Division of Oncology, Medical University of Graz, Graz, Austria.
4
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.
5
BioTechMed-Graz, Graz, Austria.

Abstract

Mitochondrial Ca2+ uptake into the mitochondrial matrix is a well-established mechanism. However, the sub-organellar Ca2+ kinetics remain elusive. In the present work we identified novel site-specific targeting sequences for the intermembrane space (IMS) and the cristae lumen (CL). We used these novel targeting peptides to develop green- and red- Ca2+ biosensors targeted to the IMS and to the CL. Based on their distinctive spectral properties, and comparable sensitivities these novel constructs were suitable to visualize Ca2+-levels in various (sub) compartments in a multi-chromatic manner. Functional studies that applied these new biosensors revealed that knockdown of MCU and EMRE yielded elevated Ca2+ levels inside the CL but not the IMS in response to IP3-generating agonists. Knockdown of VDAC1, however, strongly impeded the transfer of Ca2+ through the OMM while the cytosolic Ca2+ signal remained unchanged. The novel sub-mitochondrially targeted Ca2+ biosensors proved to be suitable for Ca2+ imaging with high spatial and temporal resolution in a multi-chromatic manner allowing simultaneous measurements. These informative biosensors will facilitate efforts to dissect the complex sub-mitochondrial Ca2+ signaling under (patho)physiological conditions.

KEYWORDS:

Ca2+; Ca2+ measurements; biosensors; live cell imaging; mitochondria; mitochondrial Ca2+; mitochondrial cristae

Supplemental Content

Full text links

Icon for Frontiers Media SA Icon for PubMed Central
Loading ...
Support Center