TY  - JOUR
A1  - Feldbauer, Katrin
A1  - Schlegel, Jan
A1  - Weissbecker, Juliane
A1  - Sauer, Frank
A1  - Wood, Phillip G.
A1  - Bamberg, Ernst
A1  - Terpitz, Ulrich
T1  - Optochemokine Tandem for Light-Control of Intracellular Ca\(^{2+}\)
JF  - PLoS ONE
N2  - An optochemokine tandem was developed to control the release of calcium from endosomes into the cytosol by light and to analyze the internalization kinetics of G-protein coupled receptors (GPCRs) by electrophysiology. A previously constructed rhodopsin tandem was re-engineered to combine the light-gated Ca\(^{2+}\)-permeable cation channel Channelrhodopsin-2(L132C), CatCh, with the chemokine receptor CXCR4 in a functional tandem protein tCXCR4/CatCh. The GPCR was used as a shuttle protein to displace CatCh from the plasma membrane into intracellular areas. As shown by patch-clamp measurements and confocal laser scanning microscopy, heterologously expressed tCXCR4/CatCh was internalized via the endocytic SDF1/CXCR4 signaling pathway. The kinetics of internalization could be followed electrophysiologically via the amplitude of the CatCh signal. The light-induced release of Ca\(^{2+}\) by tandem endosomes into the cytosol via CatCh was visualized using the Ca\(^{2+}\)-sensitive dyes rhod2 and rhod2-AM showing an increase of intracellular Ca\(^{2+}\) in response to light.
KW  - capacitance
KW  - endosomes
KW  - cell membranes
KW  - membrane proteins
KW  - intracellular membranes
KW  - vesicles
KW  - confocal laser microscopy
KW  - cytosol
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-178921
VL  - 11
IS  - 10
ER  - 
TY  - JOUR
A1  - Kato, Hiroki
A1  - Lu, Qiping
A1  - Rapaport, Doron
A1  - Kozjak-Pavlovic, Vera
T1  - Tom70 Is Essential for PINK1 Import into Mitochondria
JF  - PLoS ONE
N2  - PTEN induced kinase 1 (PINK1) is a serine/threonine kinase in the outer membrane of mitochondria (OMM), and known as a responsible gene of Parkinson's disease (PD). The precursor of PINK1 is synthesized in the cytosol and then imported into the mitochondria via the translocase of the OMM (TOM) complex. However, a large part of PINK1 import mechanism remains unclear. In this study, we examined using cell-free system the mechanism by which PINK1 is targeted to and assembled into mitochondria. Surprisingly, the main component of the import channel, Tom40 was not necessary for PINK1 import. Furthermore, we revealed that the import receptor Tom70 is essential for PINK1 import. In addition, we observed that although PINK1 has predicted mitochondrial targeting signal, it was not processed by the mitochondrial processing peptidase. Thus, our results suggest that PINK1 is imported into mitochondria by a unique pathway that is independent of the TOM core complex but crucially depends on the import receptor Tom70.
KW  - binding
KW  - outer-membrane proteins
KW  - Parkinsons diesease
KW  - intracellular membranes
KW  - quality control
KW  - pathway
KW  - recruitment
KW  - biogenesis
KW  - mechanisms
KW  - complex
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131061
VL  - 8
IS  - 3
ER  -