TY  - JOUR
A1  - Panzer, Sabine
A1  - Zhang, Chong
A1  - Konte, Tilen
A1  - Bräuer, Celine
A1  - Diemar, Anne
A1  - Yogendran, Parathy
A1  - Yu-Strzelczyk, Jing
A1  - Nagel, Georg
A1  - Gao, Shiqiang
A1  - Terpitz, Ulrich
T1  - Modified Rhodopsins From Aureobasidium pullulans Excel With Very High Proton-Transport Rates
JF  - Frontiers in Molecular Biosciences
N2  - Aureobasidium pullulans is a black fungus that can adapt to various stressful conditions like hypersaline, acidic, and alkaline environments. The genome of A. pullulans exhibits three genes coding for putative opsins ApOps1, ApOps2, and ApOps3. We heterologously expressed these genes in mammalian cells and Xenopus oocytes. Localization in the plasma membrane was greatly improved by introducing additional membrane trafficking signals at the N-terminus and the C-terminus. In patch-clamp and two-electrode-voltage clamp experiments, all three proteins showed proton pump activity with maximal activity in green light. Among them, ApOps2 exhibited the most pronounced proton pump activity with current amplitudes occasionally extending 10 pA/pF at 0 mV. Proton pump activity was further supported in the presence of extracellular weak organic acids. Furthermore, we used site-directed mutagenesis to reshape protein functions and thereby implemented light-gated proton channels. We discuss the difference to other well-known proton pumps and the potential of these rhodopsins for optogenetic applications.
KW  - black yeast
KW  - photoreceptor
KW  - microbial rhodopsins
KW  - optogenetics
KW  - proton channel
KW  - membrane trafficking
KW  - fungal rhodopsins
KW  - Aureobasidium
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-249248
SN  - 2296-889X
VL  - 8
ER  -