@article{TiegsCostelloIskenetal.2019,
  author    = {Tiegs, Scott D. and Costello, David M. and Isken, Mark W. and Woodward, Guy and McIntyre, Peter B. and Gessner, Mark O. and Chauvet, Eric and Griffiths, Natalie A. and Flecker, Alex S. and Acuna, Vicenc and Albarino, Ricardo and Allen, Daniel C. and Alonso, Cecilia and Andino, Patricio and Arango, Clay and Aroviita, Jukka and Barbosa, Marcus V. M. and Barmuta, Leon A. and Baxter, Colden V. and Bell, Thomas D. C. and Bellinger, Brent and Boyero, Luz and Brown, Lee E. and Bruder, Andreas and Bruesewitz, Denise A. and Burdon, Francis J. and Callisto, Marcos and Canhoto, Cristina and Capps, Krista A. and Castillo, Maria M. and Clapcott, Joanne and Colas, Fanny and Colon-Gaud, Checo and Cornut, Julien and Crespo-Perez, Veronica and Cross, Wyatt F. and Culp, Joseph M. and Danger, Michael and Dangles, Olivier and de Eyto, Elvira and Derry, Alison M. and Diaz Villanueva, Veronica and Douglas, Michael M. and Elosegi, Arturo and Encalada, Andrea C. and Entrekin, Sally and Espinosa, Rodrigo and Ethaiya, Diana and Ferreira, Veronica and Ferriol, Carmen and Flanagan, Kyla M. and Fleituch, Tadeusz and Shah, Jennifer J. Follstad and Frainer, Andre and Friberg, Nikolai and Frost, Paul C. and Garcia, Erica A. and Lago, Liliana Garcia and Garcia Soto, Pavel Ernesto and Ghate, Sudeep and Giling, Darren P. and Gilmer, Alan and Goncalves, Jose Francisco and Gonzales, Rosario Karina and Graca, Manuel A. S. and Grace, Mike and Grossart, Hans-Peter and Guerold, Francois and Gulis, Vlad and Hepp, Luiz U. and Higgins, Scott and Hishi, Takuo and Huddart, Joseph and Hudson, John and Imberger, Samantha and Iniguez-Armijos, Carlos and Iwata, Tomoya and Janetski, David J. and Jennings, Eleanor and Kirkwood, Andrea E. and Koning, Aaron A. and Kosten, Sarian and Kuehn, Kevin A. and Laudon, Hjalmar and Leavitt, Peter R. and Lemes da Silva, Aurea L. and Leroux, Shawn J. and Leroy, Carri J. and Lisi, Peter J. and MacKenzie, Richard and Marcarelli, Amy M. and Masese, Frank O. and Mckie, Brendan G. and Oliveira Medeiros, Adriana and Meissner, Kristian and Milisa, Marko and Mishra, Shailendra and Miyake, Yo and Moerke, Ashley and Mombrikotb, Shorok and Mooney, Rob and Moulton, Tim and Muotka, Timo and Negishi, Junjiro N. and Neres-Lima, Vinicius and Nieminen, Mika L. and Nimptsch, Jorge and Ondruch, Jakub and Paavola, Riku and Pardo, Isabel and Patrick, Christopher J. and Peeters, Edwin T. H. M. and Pozo, Jesus and Pringle, Catherine and Prussian, Aaron and Quenta, Estefania and Quesada, Antonio and Reid, Brian and Richardson, John S. and Rigosi, Anna and Rincon, Jose and Risnoveanu, Geta and Robinson, Christopher T. and Rodriguez-Gallego, Lorena and Royer, Todd V. and Rusak, James A. and Santamans, Anna C. and Selmeczy, Geza B. and Simiyu, Gelas and Skuja, Agnija and Smykla, Jerzy and Sridhar, Kandikere R. and Sponseller, Ryan and Stoler, Aaron and Swan, Christopher M. and Szlag, David and Teixeira-de Mello, Franco and Tonkin, Jonathan D. and Uusheimo, Sari and Veach, Allison M. and Vilbaste, Sirje and Vought, Lena B. M. and Wang, Chiao-Ping and Webster, Jackson R. and Wilson, Paul B. and Woelfl, Stefan and Xenopoulos, Marguerite A. and Yates, Adam G. and Yoshimura, Chihiro and Yule, Catherine M. and Zhang, Yixin X. and Zwart, Jacob A.},
  title     = {Global patterns and drivers of ecosystem functioning in rivers and riparian zones},
  series = {Science Advances},
  volume    = {5},
  journal   = {Science Advances},
  number    = {1},
  publisher = {American Assoc. for the Advancement of Science},
  address   = {Washington},
  issn      = {2375-2548},
  doi       = {10.1126/sciadv.aav0486},
  pages     = {8},
  year      = {2019},
  abstract  = {River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.},
  language  = {en}
}
@article{vonLoeffelholzLieskeNeuschaeferRubeetal.2017,
  author    = {von Loeffelholz, Christian and Lieske, Stefanie and Neuschaefer-Rube, Frank and Willmes, Diana M. and Raschzok, Nathanael and Sauer, Igor M. and K{\"o}nig, J{\"o}rg and Fromm, Martin F. and Horn, Paul and Chatzigeorgiou, Antonios and Pathe-Neuschaefer-Rube, Andrea and Jordan, Jens and Pfeiffer, Andreas F. H. and Mingrone, Geltrude and Bornstein, Stefan R. and Stroehle, Peter and Harms, Christoph and Wunderlich, F. Thomas and Helfand, Stephen L. and Bernier, Michel and de Cabo, Rafael and Shulman, Gerald I. and Chavakis, Triantafyllos and P{\"u}schel, Gerhard Paul and Birkenfeld, Andreas L.},
  title     = {The human longevity gene homolog INDY and interleukin-6 interact in hepatic lipid metabolism},
  series = {Hepatology},
  volume    = {66},
  journal   = {Hepatology},
  number    = {2},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0270-9139},
  doi       = {10.1002/hep.29089},
  pages     = {616 -- 630},
  year      = {2017},
  abstract  = {Reduced expression of the Indy ("I am Not Dead, Yet") gene in lower organisms promotes longevity in a manner akin to caloric restriction. Deletion of the mammalian homolog of Indy (mIndy, Slc13a5) encoding for a plasma membrane-associated citrate transporter expressed highly in the liver, protects mice from high-fat diet-induced and aging-induced obesity and hepatic fat accumulation through a mechanism resembling caloric restriction. We studied a possible role of mIndy in human hepatic fat metabolism. In obese, insulin-resistant patients with nonalcoholic fatty liver disease, hepatic mIndy expression was increased and mIndy expression was also independently associated with hepatic steatosis. In nonhuman primates, a 2-year high-fat, high-sucrose diet increased hepatic mIndy expression. Liver microarray analysis showed that high mIndy expression was associated with pathways involved in hepatic lipid metabolism and immunological processes. Interleukin-6 (IL-6) was identified as a regulator of mIndy by binding to its cognate receptor. Studies in human primary hepatocytes confirmed that IL-6 markedly induced mIndy transcription through the IL-6 receptor and activation of the transcription factor signal transducer and activator of transcription 3, and a putative start site of the human mIndy promoter was determined. Activation of the IL-6-signal transducer and activator of transcription 3 pathway stimulated mIndy expression, enhanced cytoplasmic citrate influx, and augmented hepatic lipogenesis in vivo. In contrast, deletion of mIndy completely prevented the stimulating effect of IL-6 on citrate uptake and reduced hepatic lipogenesis. These data show that mIndy is increased in liver of obese humans and nonhuman primates with NALFD. Moreover, our data identify mIndy as a target gene of IL-6 and determine novel functions of IL-6 through mINDY. Conclusion: Targeting human mINDY may have therapeutic potential in obese patients with nonalcoholic fatty liver disease. German Clinical Trials Register: DRKS00005450.},
  language  = {en}
}
@article{FrodlJanowitzSchmaaletal.2017,
  author    = {Frodl, Thomas and Janowitz, Deborah and Schmaal, Lianne and Tozzi, Leonardo and Dobrowolny, Henrik and Stein, Dan J. and Veltman, Dick J. and Wittfeld, Katharina and van Erp, Theo G. M. and Jahanshad, Neda and Block, Andrea and Hegenscheid, Katrin and Voelzke, Henry and Lagopoulos, Jim and Hatton, Sean N. and Hickie, Ian B. and Frey, Eva Maria and Carballedo, Angela and Brooks, Samantha J. and Vuletic, Daniella and Uhlmann, Anne and Veer, Ilya M. and Walter, Henrik and Schnell, Knut and Grotegerd, Dominik and Arolt, Volker and Kugel, Harald and Schramm, Elisabeth and Konrad, Carsten and Zurowski, Bartosz and Baune, Bernhard T. and van der Wee, Nic J. A. and van Tol, Marie-Jose and Penninx, Brenda W. J. H. and Thompson, Paul M. and Hibar, Derrek P. and Dannlowski, Udo and Grabe, Hans J.},
  title     = {Childhood adversity impacts on brain subcortical structures relevant to depression},
  series = {Journal of psychiatric research},
  volume    = {86},
  journal   = {Journal of psychiatric research},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0022-3956},
  doi       = {10.1016/j.jpsychires.2016.11.010},
  pages     = {58 -- 65},
  year      = {2017},
  abstract  = {Childhood adversity plays an important role for development of major depressive disorder (MDD). There are differences in subcortical brain structures between patients with MDD and healthy controls, but the specific impact of childhood adversity on such structures in MDD remains unclear. Thus, aim of the present study was to investigate whether childhood adversity is associated with subcortical volumes and how it interacts with a diagnosis of MDD and sex. Within the ENIGMA-MDD network, nine university partner sites, which assessed childhood adversity and magnetic resonance imaging in patients with MDD and controls, took part in the current joint mega-analysis. In this largest effort world-wide to identify subcortical brain structure differences related to childhood adversity, 3036 participants were analyzed for subcortical brain volumes using FreeSurfer. A significant interaction was evident between childhood adversity, MDD diagnosis, sex, and region. Increased exposure to childhood adversity was associated with smaller caudate volumes in females independent of MDD. All subcategories of childhood adversity were negatively associated with caudate volumes in females - in particular emotional neglect and physical neglect (independently from age, ICV, imaging site and MDD diagnosis). There was no interaction effect between childhood adversity and MDD diagnosis on subcortical brain volumes. Childhood adversity is one of the contributors to brain structural abnormalities. It is associated with subcortical brain abnormalities that are relevant to psychiatric disorders such as depression. (C) 2016 Published by Elsevier Ltd.},
  language  = {en}
}
@article{CreightonParsekianAngelopoulosetal.2018,
  author    = {Creighton, Andrea L. and Parsekian, Andrew D. and Angelopoulos, Michael and Jones, Benjamin M. and Bondurant, A. and Engram, M. and Lenz, Josefine and Overduin, Pier Paul and Grosse, Guido and Babcock, E. and Arp, Christopher D.},
  title     = {Transient Electromagnetic Surveys for the Determination of Talik Depth and Geometry Beneath Thermokarst Lakes},
  series = {Journal of geophysical research : Solid earth},
  volume    = {123},
  journal   = {Journal of geophysical research : Solid earth},
  number    = {11},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {2169-9313},
  doi       = {10.1029/2018JB016121},
  pages     = {9310 -- 9323},
  year      = {2018},
  abstract  = {Thermokarst lakes are prevalent in Arctic coastal lowland regions and sublake permafrost degradation and talik development contributes to greenhouse gas emissions by tapping the large permafrost carbon pool. Whereas lateral thermokarst lake expansion is readily apparent through remote sensing and shoreline measurements, sublake thawed sediment conditions and talik growth are difficult to measure. Here we combine transient electromagnetic surveys with thermal modeling, backed up by measured permafrost properties and radiocarbon ages, to reveal closed-talik geometry associated with a thermokarst lake in continuous permafrost. To improve access to talik geometry data, we conducted surveys along three transient electromagnetic transects perpendicular to lakeshores with different decadal-scale expansion rates of 0.16, 0.38, and 0.58m/year. We modeled thermal development of the talik using boundary conditions based on field data from the lake, surrounding permafrost and a borehole, independent of the transient electromagnetics. A talik depth of 91m was determined from analysis of the transient electromagnetic surveys. Using a lake initiation age of 1400years before present and available subsurface properties the results from thermal modeling of the lake center arrived at a best estimate talk depth of 80m, which is on the same order of magnitude as the results from the transient electromagnetic survey. Our approach has provided a noninvasive estimate of talik geometry suitable for comparable settings throughout circum-Arctic coastal lowland regions.},
  language  = {en}
}
@misc{PatheNeuschaeferRubeNeuschaeferRubeHaasetal.2018,
  author    = {Pathe-Neusch{\"a}fer-Rube, Andrea and Neusch{\"a}fer-Rube, Frank and Haas, Gerald and Langoth-Fehringer, Nina and P{\"u}schel, Gerhard Paul},
  title     = {Cell-Based Reporter Release Assay to Determine the Potency of Proteolytic Bacterial Neurotoxins},
  series = {Toxins},
  journal   = {Toxins},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418141},
  pages     = {10},
  year      = {2018},
  abstract  = {Despite the implementation of cell-based replacement methods, the mouse lethality assay is still frequently used to determine the activity of botulinum toxin (BoNT) for medical use. One explanation is that due to the use of neoepitope-specific antibodies to detect the cleaved BoNT substrate, the currently devised assays can detect only one specific serotype of the toxin. Recently, we developed a cell-based functional assay, in which BoNT activity is determined by inhibiting the release of a reporter enzyme that is liberated concomitantly with the neurotransmitter from neurosecretory vesicles. In theory, this assay should be suitable to detect the activity of any BoNT serotype. Consistent with this assumption, the current study shows that the stimulus-dependent release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) was inhibited by BoNT-A and-C. Furthermore, this was also inhibited by BoNT-B and tetanus toxin to a lesser extent and at higher concentrations. In order to provide support for the suitability of this technique in practical applications, a dose-response curve obtained with a pharmaceutical preparation of BoNT-A closely mirrored the activity determined in the mouse lethality assay. In summary, the newly established cell-based assay may represent a versatile and specific alternative to the mouse lethality assay and other currently established cell-based assays.},
  language  = {en}
}
@article{HenkelNeuschaeferRubePatheNeuschaeferRubeetal.2009,
  author    = {Henkel, Janin and Neuschaefer-Rube, Frank and Pathe-Neuschaefer-Rube, Andrea and P{\"u}schel, Gerhard Paul},
  title     = {Aggravation by prostaglandin e-2 of interleukin-6-dependent insulin resistance in hepatocytes},
  issn      = {0270-9139},
  doi       = {10.1002/Hep.23064},
  year      = {2009},
  abstract  = {Hepatic insulin resistance is a major contributor to fasting hyperglycemia in patients with metabolic syndrome and type 2 diabetes. Circumstantial evidence suggests that cyclooxygenase products in addition to cytokines might contribute to insulin resistance. However, direct evidence for a role of prostaglandins in the development of hepatic insulin resistance is lacking. Therefore, the impact of prostaglandin E-2 (PGE(2)) alone and in combination with interleukin-6 (IL-6) on insulin signaling was studied in primary hepatocyte cultures. Rat hepatocytes were incubated with IL-6 and/or PGE(2) and subsequently with insulin. Glycogen synthesis was monitored by radiochemical analysis; the activation state of proteins of the insulin receptor signal chain was analyzed by western blot with phosphospecific antibodies. In hepatocytes, insulin-stimulated glycogen synthesis and insulin-dependent phosphorylation of Akt-kinase were attenuated synergistically by prior incubation with IL-6 and/or PGE(2) while insulin receptor autophosphorylation was barely affected. IL-6 but not PGE(2) induced suppressors of cytokine signaling (SOCS3). PGE(2) but not IL-6 activated extracellular signal-regulated kinase 1/2 (ERK1/2) persistently. Inhibition of ERK1/2 activation by PD98059 abolished the PGE(2)-dependent but not the IL-6-dependent attenuation of insulin signaling. In HepG2 cells expressing a recombinant EP3-receptor, PGE(2) pre-incubation activated ERK1/2, caused a serine phosphorylation of insulin receptor substrate 1 (IRS1), and reduced the insulin-dependent Akt-phosphorylation. Conclusion: PGE(2) might contribute to hepatic insulin resistance via an EP3-receptor-dependent ERK1/2 activation resulting in a serine phosphorylation of insulin receptor substrate, thereby preventing an insulin-dependent activation of Akt and glycogen synthesis. Since different molecular mechanisms appear to be employed, PGE(2) may synergize with IL-6, which interrupted the insulin receptor signal chain, principally by an induction of SOCS, namely SOCS3.},
  language  = {en}
}
@article{PatheNeuschaeferRubeNeuschaeferRubeGenzetal.2015,
  author    = {Pathe-Neuschaefer-Rube, Andrea and Neuschaefer-Rube, Frank and Genz, Lara and P{\"u}schel, Gerhard Paul},
  title     = {Botulinum Neurotoxin Dose-Dependently Inhibits Release of Neurosecretory Vesicle-Targeted Luciferase from Neuronal Cells},
  series = {Alternatives to animal experimentation : ALTEX ; a journal for new paths in biomedical science},
  volume    = {32},
  journal   = {Alternatives to animal experimentation : ALTEX ; a journal for new paths in biomedical science},
  number    = {4},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1868-596X},
  pages     = {297 -- 306},
  year      = {2015},
  abstract  = {Botulinum toxin is a bacterial toxin that inhibits neurotransmitter release from neurons and thereby causes a flaccid paralysis. It is used as drug to treat a number of serious ailments and, more frequently, for aesthetic medical interventions. Botulinum toxin for pharmacological applications is isolated from bacterial cultures. Due to partial denaturation of the protein, the specific activity of these preparations shows large variations. Because of its extreme potential toxicity, pharmacological preparations must be carefully tested for their activity. For the current gold standard, the mouse lethality assay, several hundred thousand mice are killed per year. Alternative methods have been developed that suffer from one or more of the following deficits: In vitro enzyme assays test only the activity of the catalytic subunit of the toxin. Enzymatic and cell based immunological assays are specific for just one of the different serotypes. The current study takes a completely different approach that overcomes these limitations: Neuronal cell lines were stably transfected with plasmids coding for luciferases of different species, which were N-terminally tagged with leader sequences that redirect the luciferase into neuro-secretory vesicles. From these vesicles, luciferases were released upon depolarization of the cells. The depolarization-dependent release was efficiently inhibited by botulinum toxin in a concentration range (1 to 100 pM) that is used in pharmacological preparations. The new assay might thus be an alternative to the mouse lethality assay and the immunological assays already in use.},
  language  = {en}
}
@article{PatheNeuschaeferRubeNeuschaeferRubeHaasetal.2018,
  author    = {Pathe-Neusch{\"a}fer-Rube, Andrea and Neusch{\"a}fer-Rube, Frank and Haas, Gerald and Langoth-Fehringer, Nina and P{\"u}schel, Gerhard Paul},
  title     = {Cell-Based Reporter Release Assay to Determine the Potency of Proteolytic Bacterial Neurotoxins},
  series = {Toxins},
  volume    = {10},
  journal   = {Toxins},
  number    = {9},
  publisher = {Molecular Diversity Preservation International (MDPI)},
  address   = {Basel},
  issn      = {2072-6651},
  doi       = {10.3390/toxins10090360},
  pages     = {1 -- 10},
  year      = {2018},
  abstract  = {Despite the implementation of cell-based replacement methods, the mouse lethality assay is still frequently used to determine the activity of botulinum toxin (BoNT) for medical use. One explanation is that due to the use of neoepitope-specific antibodies to detect the cleaved BoNT substrate, the currently devised assays can detect only one specific serotype of the toxin. Recently, we developed a cell-based functional assay, in which BoNT activity is determined by inhibiting the release of a reporter enzyme that is liberated concomitantly with the neurotransmitter from neurosecretory vesicles. In theory, this assay should be suitable to detect the activity of any BoNT serotype. Consistent with this assumption, the current study shows that the stimulus-dependent release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) was inhibited by BoNT-A and-C. Furthermore, this was also inhibited by BoNT-B and tetanus toxin to a lesser extent and at higher concentrations. In order to provide support for the suitability of this technique in practical applications, a dose-response curve obtained with a pharmaceutical preparation of BoNT-A closely mirrored the activity determined in the mouse lethality assay. In summary, the newly established cell-based assay may represent a versatile and specific alternative to the mouse lethality assay and other currently established cell-based assays.},
  language  = {en}
}
@article{PatheNeuschaeferRubeNeuschaeferRubePueschel2005,
  author    = {Pathe-Neusch{\"a}fer-Rube, Andrea and Neusch{\"a}fer-Rube, Frank and P{\"u}schel, Gerhard Paul},
  title     = {Role of the ERC motif in the proximal part of the second intracellular loop and the C-terminal domain of the human prostaglandin F2alpha receptor (hFP-R) in G-protein coupling control},
  year      = {2005},
  abstract  = {The human FP-R (F2alpha prostaglandin receptor) is a Gq-coupled heptahelical ectoreceptor, which is of significant medical interest, since it is a potential target for the treatment of glaucoma and preterm labour. On agonist exposure, it mediates an increase in intracellular inositol phosphate formation. Little is known about the structures that govern the agonist-dependent receptor activation. In other prostanoid receptors, the C-terminal domain has been inferred in the control of agonist-dependent receptor activation. A DRY motif at the beginning of the second intracellular loop is highly conserved throughout the G-protein-coupled receptor family and appears to be crucial for controlling agonist-dependent receptor activation. It is replaced by an ERC motif in the FP-R and no evidence for the relevance of this motif in ligand-dependent activation of prostanoid receptors has been provided so far. The aim of the present study was to elucidate the potential role of the C-terminal domain and the ERC motif in agonist-controlled intracellular signalling in FP-R mutants generated by site-directed mutagenesis. It was found that substitution of the acidic Glu(132) in the ERC motif by a threonine residue led to full constitutive activation, whereas truncation of the receptor's C-terminal domain led to partial constitutive activation of all three intracellular signal pathways that had previously been shown to be activated by the FP-R, i.e. inositol trisphosphate formation, focal adhesion kinase activation and T-cell factor signalling. Inositol trisphosphate formation and focal adhesion kinase phosphorylation were further enhanced by ligand binding in cells expressing the truncation mutant but not the E132T (Glu132-->Thr) mutant. Thus C-terminal truncation appeared to result in a receptor with partial constitutive activation, whereas substitution of Glu132 by threonine apparently resulted in a receptor with full constitutive activity.},
  language  = {en}
}
@article{NeuschaeferRubeHermosillaKunaetal.2005,
  author    = {Neusch{\"a}fer-Rube, Frank and Hermosilla, Ricardo and Kuna, Manuela and Pathe-Neusch{\"a}fer-Rube, Andrea and Schulein, R. and P{\"u}schel, Gerhard Paul},
  title     = {A Ser/Thr cluster within the C-terminal domain of the rat prostaglandin receptor EP3 alpha is essential for agonist-induced phosphorylation, desensitization and internalization},
  issn      = {0007-1188},
  year      = {2005},
  abstract  = {1 Two isoforms of the rat prostaglandin E-2 receptor, rEP3 alpha-R and rEP3 beta-R, differ only in their C- terminal domain. To analyze the function of the rEP3-R C-terminal domain in agonist induced desensitization, a cluster of Ser/Thr residues in the C-terminal domain of the rEP3 alpha-R was mutated to Ala and both isoforms and the receptor mutant (rEP3 alpha-ST341-349A-R) were stably expressed in HEK293 cells. 2 All rEP3-R receptors showed a similar ligand- binding profile. They were functionally coupled to Gi and reduced forskolin-induced cAMP-formation. 3 Repeated exposure of cells expressing the rEP3 alpha-R isoform to PGE(2) reduced the agonist induced inhibition of forskolin-stimulated cAMP-formation by 50\% and led to internalization of the receptor to intracellular endocytotic vesicles. By contrast, Gi- response as well as plasma membrane localization of the rEP3 beta-R and the rEP3 alpha-ST341-349A-R were not affected by prior agonist-stimulation. 4 Agonist-stimulation of HEK293-rEP3 alpha-R cells induced a time- and dose-dependent phosphorylation of the receptor most likely by G protein-coupled receptor kinases and not by protein kinase A or protein kinase C. By contrast, upon agonist-stimulation the rEP3 beta-R was not phosphorylated and the rEP3 alpha-ST341-349A-R was phosphorylated only weakly. 5 These results led to the hypothesis that agonist-induced desensitization of the rEP3 alpha-R isoform is mediated most likely by a GRK-dependent phosphorylation of Ser/Thr residues 341 - 349. Phosphorylation then initiates uncoupling of the receptor from Gi protein and receptor internalization},
  language  = {en}
}