@article{AdamDeimelPardoMedinaetal.2018,
  author    = {Adam, Alexander and Deimel, Stephan and Pardo-Medina, Javier and Garc{\´i}a-Mart{\´i}nez, Jorge and Konte, Tilen and Lim{\´o}n, M. Carmen and Avalos, Javier and Terpitz, Ulrich},
  title     = {Protein activity of the \(Fusarium\) \(fujikuroi\) rhodopsins CarO and OpsA and their relation to fungus-plant interaction},
  series = {International Journal of Molecular Sciences},
  volume    = {19},
  journal   = {International Journal of Molecular Sciences},
  number    = {1},
  issn      = {1422-0067},
  doi       = {10.3390/ijms19010215},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285125},
  year      = {2018},
  abstract  = {Fungi possess diverse photosensory proteins that allow them to perceive different light wavelengths and to adapt to changing light conditions in their environment. The biological and physiological roles of the green light-sensing rhodopsins in fungi are not yet resolved. The rice plant pathogen Fusarium fujikuroi exhibits two different rhodopsins, CarO and OpsA. CarO was previously characterized as a light-driven proton pump. We further analyzed the pumping behavior of CarO by patch-clamp experiments. Our data show that CarO pumping activity is strongly augmented in the presence of the plant hormone indole-3-acetic acid and in sodium acetate, in a dose-dependent manner under slightly acidic conditions. By contrast, under these and other tested conditions, the Neurospora rhodopsin (NR)-like rhodopsin OpsA did not exhibit any pump activity. Basic local alignment search tool (BLAST) searches in the genomes of ascomycetes revealed the occurrence of rhodopsin-encoding genes mainly in phyto-associated or phytopathogenic fungi, suggesting a possible correlation of the presence of rhodopsins with fungal ecology. In accordance, rice plants infected with a CarO-deficient F. fujikuroi strain showed more severe bakanae symptoms than the reference strain, indicating a potential role of the CarO rhodopsin in the regulation of plant infection by this fungus.},
  language  = {en}
}
@article{PanzerBrychBatschaueretal.2019,
  author    = {Panzer, Sabine and Brych, Annika and Batschauer, Alfred and Terpitz, Ulrich},
  title     = {Opsin 1 and Opsin 2 of the corn smut fungus ustilago maydis are green light-driven proton pumps},
  series = {Frontiers in Microbiology},
  volume    = {10},
  journal   = {Frontiers in Microbiology},
  doi       = {10.3389/fmicb.2019.00735},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201453},
  pages     = {735},
  year      = {2019},
  abstract  = {In fungi, green light is absorbed by rhodopsins, opsin proteins carrying a retinal molecule as chromophore. The basidiomycete Ustilago maydis, a fungal pathogen that infects corn plants, encodes three putative photoactive opsins, called ops1 (UMAG_02629), ops2 (UMAG_00371), and ops3 (UMAG_04125). UmOps1 and UmOps2 are expressed during the whole life cycle, in axenic cultures as well as in planta, whereas UmOps3 was recently shown to be absent in axenic cultures but highly expressed during plant infection. Here we show that expression of UmOps1 and UmOps2 is induced by blue light under control of white collar 1 (Wco1). UmOps1 is mainly localized in the plasma membrane, both when expressed in HEK cells and U. maydis sporidia. In contrast, UmOps2 was mostly found intracellularly in the membranes of vacuoles. Patch-clamp studies demonstrated that both rhodopsins are green light-driven outward rectifying proton pumps. UmOps1 revealed an extraordinary pH dependency with increased activity in more acidic environment. Also, UmOps1 showed a pronounced, concentration-dependent enhancement of pump current caused by weak organic acids (WOAs), especially by acetic acid and indole-3-acetic acid (IAA). In contrast, UmOps2 showed the typical behavior of light-driven, outwardly directed proton pumps, whereas UmOps3 did not exhibit any electrogenity. With this work, insights were gained into the localization and molecular function of two U. maydis rhodopsins, paving the way for further studies on the biological role of these rhodopsins in the life cycle of U. maydis.},
  language  = {en}
}
@article{PanzerZhangKonteetal.2021,
  author    = {Panzer, Sabine and Zhang, Chong and Konte, Tilen and Br{\"a}uer, Celine and Diemar, Anne and Yogendran, Parathy and Yu-Strzelczyk, Jing and Nagel, Georg and Gao, Shiqiang and Terpitz, Ulrich},
  title     = {Modified Rhodopsins From Aureobasidium pullulans Excel With Very High Proton-Transport Rates},
  series = {Frontiers in Molecular Biosciences},
  volume    = {8},
  journal   = {Frontiers in Molecular Biosciences},
  issn      = {2296-889X},
  doi       = {10.3389/fmolb.2021.750528},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-249248},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}