@article{MilanosElsharifJanzenetal.2017,
  author    = {Milanos, Sinem and Elsharif, Shaimaa A. and Janzen, Dieter and Buettner, Andrea and Villmann, Carmen},
  title     = {Metabolic Products of Linalool and Modulation of GABA\(_{A}\) Receptors},
  series = {Frontiers in Chemistry},
  volume    = {5},
  journal   = {Frontiers in Chemistry},
  number    = {46},
  doi       = {10.3389/fchem.2017.00046},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170779},
  year      = {2017},
  abstract  = {Terpenoids are major subcomponents in aroma substances which harbor sedative physiological potential. We have demonstrated that various monoterpenoids such as the acyclic linalool enhance GABAergic currents in an allosteric manner in vitro upon overexpression of inhibitory α1β2 GABA\(_{A}\) receptors in various expression systems. However, in plants or humans, i.e., following intake via inhalation or ingestion, linalool undergoes metabolic modifications including oxygenation and acetylation, which may affect the modulatory efficacy of the generated linalool derivatives. Here, we analyzed the modulatory potential of linalool derivatives at α1β2γ2 GABA\(_{A}\) receptors upon transient overexpression. Following receptor expression control, electrophysiological recordings in a whole cell configuration were used to determine the chloride influx upon co-application of GABA EC\(_{10-30}\) together with the modulatory substance. Our results show that only oxygenated linalool metabolites at carbon 8 positively affect GABAergic currents whereas derivatives hydroxylated or carboxylated at carbon 8 were rather ineffective. Acetylated linalool derivatives resulted in non-significant changes of GABAergic currents. We can conclude that metabolism of linalool reduces its positive allosteric potential at GABAA receptors compared to the significant potentiation effects of the parent molecule linalool itself.},
  language  = {en}
}
@article{DrehmannMilanosSchaeferetal.2023,
  author    = {Drehmann, Paul and Milanos, Sinem and Schaefer, Natascha and Kasaragod, Vikram Babu and Herterich, Sarah and Holzbach-Eberle, Ulrike and Harvey, Robert J. and Villmann, Carmen},
  title     = {Dual role of dysfunctional Asc-1 transporter in distinct human pathologies, human startle disease, and developmental delay},
  series = {eNeuro},
  volume    = {10},
  journal   = {eNeuro},
  number    = {11},
  doi       = {10.1523/ENEURO.0263-23.2023},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349947},
  year      = {2023},
  abstract  = {Human startle disease is associated with mutations in distinct genes encoding glycine receptors, transporters or interacting proteins at glycinergic synapses in spinal cord and brainstem. However, a significant number of diagnosed patients does not carry a mutation in the common genes GLRA1, GLRB, and SLC6A5. Recently, studies on solute carrier 7 subfamily 10 (SLC7A10; Asc-1, alanine-serine-cysteine transporter) knock-out (KO) mice displaying a startle disease-like phenotype hypothesized that this transporter might represent a novel candidate for human startle disease. Here, we screened 51 patients from our patient cohort negative for the common genes and found three exonic (one missense, two synonymous), seven intronic, and single nucleotide changes in the 5′ and 3′ untranslated regions (UTRs) in Asc-1. The identified missense mutation Asc-1\(^{G307R}\) from a patient with startle disease and developmental delay was investigated in functional studies. At the molecular level, the mutation Asc-1\(^{G307R}\) did not interfere with cell-surface expression, but disrupted glycine uptake. Substitution of glycine at position 307 to other amino acids, e.g., to alanine or tryptophan did not affect trafficking or glycine transport. By contrast, G307K disrupted glycine transport similar to the G307R mutation found in the patient. Structurally, the disrupted function in variants carrying positively charged residues can be explained by local structural rearrangements because of the large positively charged side chain. Thus, our data suggest that SLC7A10 may represent a rare but novel gene associated with human startle disease and developmental delay.},
  language  = {en}
}