TY  - JOUR
A1  - García-Martínez, Jorge
A1  - Brunk, Michael
A1  - Avalos, Javier
A1  - Terpitz, Ulrich
T1  - The CarO rhodopsin of the fungus Fusarium fujikuroi is a light-driven proton pump that retards spore germination
JF  - Scientific Reports
N2  - Rhodopsins are membrane-embedded photoreceptors found in all major taxonomic kingdoms using retinal as their chromophore. They play well-known functions in different biological systems, but their roles in fungi remain unknown. The filamentous fungus Fusarium fujikuroi contains two putative rhodopsins, CarO and OpsA. The gene carO is light-regulated, and the predicted polypeptide contains all conserved residues required for proton pumping. We aimed to elucidate the expression and cellular location of the fungal rhodopsin CarO, its presumed proton-pumping activity and the possible effect of such function on F. fujikuroi growth. In electrophysiology experiments we confirmed that CarO is a green-light driven proton pump. Visualization of fluorescent CarO-YFP expressed in F. fujikuroi under control of its native promoter revealed higher accumulation in spores (conidia) produced by light-exposed mycelia. Germination analyses of conidia from carO\(^{-}\) mutant and carO\(^{+}\) control strains showed a faster development of light-exposed carO-germlings. In conclusion, CarO is an active proton pump, abundant in light-formed conidia, whose activity slows down early hyphal development under light. Interestingly, CarO-related rhodopsins are typically found in plant-associated fungi, where green light dominates the phyllosphere. Our data provide the first reliable clue on a possible biological role of a fungal rhodopsin.
KW  - microbial rhodopsins
KW  - intracellular pH
KW  - membrane proteins
KW  - mutants
KW  - virulence
KW  - channelrhodopsin-2
KW  - growth
KW  - gene
KW  - expression
KW  - bacteriorhodopsin
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149049
VL  - 5
IS  - 7798
ER  - 
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  -